Light-emitting diode, led light, and light apparatus

ABSTRACT

An LED light comprising a light-emitting device provided to power supply means, encapsulating means for encapsulating the light-emitting device with a light-transmitting material, a reflective surface for reflecting the light emitted from the light-emitting device to a direction perpendicular to the center axis of the light-emitting device or at a large angle to the center axis, opposed to the light-emitting surface of the light-emitting device, a light-emitting diode having a side directing surface for directing sideways the light reflected from the reflective surface to a direction perpendicular to the center axis of the light-emitting device or at a large angle to the center axis, and a reflecting mirror disposed around the light-emitting diode.

TECHNICAL FIELD

This invention relates to a package resin (hereinafter also referred toas light emitting diode or LED) with a light emitting element(hereinafter also referred to as LED chip) installed therein, and an LEDlight (hereinafter also referred to as light emitting unit) that the LEDis used as a light source, and a lamp that is composed using the LEDlight and can be applied as an automobile tail lamp or stop lamp etc.

BACKGROUND ART

Along with the development of high-brightness light emitting element, anLED light using LED as a light source is progressively used for anautomobile rear lamp etc. LED offers a good visibility due to its sharpspectrum. Also, it has a high signaling speed to a following vehiclesince the response speed is high, and it has a significant effect inreducing the braking distance in the case of high-speed driving.Further, since LED itself is a monochromatic light source, it is notnecessary to cut light color other than desired color by using a filteras is the case with an electrical light bulb. Thus, it can be amonochromatic light source with high efficiency and can save energy.

FIG. 103 shows an example of the LED light. As shown in FIG. 103, a LEDlight 1000 uses, as a light source, a lens-type LED 1010 that a lightemitting element 1020 is sealed with transparent epoxy resin 1050 whilebeing formed of a convex lens. The lens-type LED 1010 is fabricated suchthat the light emitting element 1020 is mounted on a lead 1030 a of apair of leads 1030 a, 1030 b, the light emitting element 1020 is bondedto the lead 1030 b through a wire 104, and the entire LED is sealed withtransparent resin 1050 while being formed of a convex lens. A reflectionmirror 1060 with paraboloid is disposed around the lens type LED 1010,and a Fresnel lens 1070 is disposed over the LED 1010. In the abovecomposition, light to be radiated from the lens type LED 1010 isreflected by the reflection mirror 1060 or converged by the Fresnel lens1070, and is all radiated upward nearly in parallel. Then, light istransmitted through a resin lens 1090 while being diffused by an uneveninterface that is formed on the bottom surface of resin lens 1090, andis externally radiated having a diffusion angle of about 20 degrees tomeet the regulation for vehicle rear lamp.

On the other hand, as the output of light emitting element is furtherenhanced, it is desired to cover a predetermined emission area by usinga reduced number of light emitting element. This aims to reduce thenumber of parts and to save labor in mounting parts.

However, in the LED light 1000 described above, if it is tried to useone light emitting element to cover a large area, its dimensionincreases at a homothetic ratio both in the width direction and in thedepth direction. Further, if it is tried to forcedly make itlow-profile, its appearance is spoiled. Therefore, there is a problemthat it is difficult to provide a low-profile light source which is acharacteristic of LED. In addition, light not heading from the lightemitting element 1020 to the reflection mirror 1060 or Fresnel lens 1070cannot be optically controlled and cannot be, therefore, externallyradiated. Thus, there is a further problem in external radiationefficiency.

To solve these problems, Japanese patent application laid-open No.2001-93312 discloses an LED light.

FIG. 104 shows the LED light disclosed therein. FIG. 104 (a) is a crosssectional view showing the LED light with a light source centered. FIG.104( b) is a perspective view showing part of the LED light. The LEDlight is composed of: the light source 1100; a first reflection surface1110 that is disposed at a position on the center axis of light source1100 while being opposite to the light source 1100 and that has aparabolic reflection surface 1110 a to allow light radiated from thelight source 1100 to be reflected in the Y direction nearly orthogonalto the center axis X of light source 1100; and a second reflectionsurface 1120 that is disposed around the first reflection surface 1110and that has a plurality of reflection facets 1120 a to allow lightreflected by the first reflection surface 1110 to be reflected in thedirection of center axis X. In this composition, light to be radiatedfrom the light source 1100 is reflected in the Y direction by theparabolic reflection surface 1110 a of first reflection surface 1110,and then the reflected light is reflected in the direction of centeraxis X by the reflection facets 1120 a of second reflection surface1120. Thus, vehicle signaling light with a predetermined radiation anglecan be radiated over a predetermined area.

However, in the LED light, there is a problem that light directlyradiated from the light source 1100 cannot be taken out in theperpendicular direction because of being blocked by the first reflectionsurface 1110 disposed over the light source 1100 and, therefore, a darkportion is generated at the center.

To solve this problem, International Publication No. 99/09349 disclosesan LED light.

FIG. 105 shows the LED light disclosed therein. FIG. 105( a) is a crosssectional view showing the LED light with a light source centered. FIG.105( b) is a cross sectional view cut along the line K-K in FIG. 105(a). The LED light is composed of: a light source 1620 that has a lightemitting element 1600, light emitting source, a dome section 1610 and abase section 1610A; a lens element 1740 that has an incident surface1630, a first reflection region 1640, a first reflection surface 1640A,a direct transmitting region 1650, a second reflection region 1660, aradiation surface 1670, an edge 168, and posts 1720, 1730; and anoptical element 1750 that pillow lenses 1750A are arrayed. The secondreflection region 1660 of lens element 1740 has pairs of an extractionsurface 1660A and a step down 1660B that are formed 360 degrees aroundthe first reflection region 1640. Further, as shown in FIG. 105( b), thelight source 1620 is composed such that the dome section 1610 ispositioned at the center of first reflection region 1640 by fitting theposts 1720, 1730 of lens element 1740 into recesses 1620A, 1620B of thebase section 1610A.

In this composition, light to be radiated from the light source 1620 isreflected by the first reflection surface 1640A in a directionorthogonal to the center axis of light source 1620. Then, reflectedlight is further reflected by the extraction surface 1660A in the centeraxis direction to be radiated as light A from the radiation surface1670. On the other hand, light B from the light source 1620 is directlytransmitted though the direct transmitting region 1650 to be radiated inthe center axis direction. Thus, light with an enlarged radiation areais entered into the optical element 1750.

However, in the above LED light, there is a problem that the entirethickness must be increased since there is provided the dome section1610 to converge light radiated from the light source 1620 to the centeraxis.

Further, it is difficult to perfectly align the center axis of lenselement 1740 with the center axis of light source 1620 in fabricationand, therefore, a deviation in position may occur and uniformity inbrightness is difficult to obtain over all directions. Namely, the lightsource 1620 and lens element 1740 are separately prepared and thenaligned with each other in fabrication. If a precision in alignment ofthe center axis of light source 1620 with the first reflection region1640 of lens element 1740 lowers, the amount of reflected light in allreflection directions given by the first reflection region 1640 becomesuneven and unevenness (difference) in brightness will occur on thesurface of LED light. Especially in the case of optical system with sucha high light focusing characteristic that most of light radiated fromthe light source 1620 is radiated upward, there occurs a significantdifference in brightness due to unevenness in the light distribution oflight source 1620 itself or due to unevenness in optical characteristicsthereof caused by a deviation in position in a direction perpendicularto the center axis between the lens element 1740 and the light source1620. Namely, in the above LED light, since light form the lightemitting element 1600 is radiated being focused by the dome section1610, there may occur a significant difference in the distribution oflight to be radiated from the dome section 1610 even when a slightdeviation in position is generated between the center axis of lightsource 1600 and the center axis of dome section 1610. As describedabove, it has a potential problem that the structure of light source1620 itself may cause a difference in light distribution characteristic.In addition, due to a deviation in position in mounting the lens element1740 separately prepared, there occurs a problem that the amount ofreflected light in all reflection directions given by the firstreflection region 1640 becomes uneven.

Further, there are problems that the light utilization efficiency lowersdue to sideward light not enabled to be focused on the center axis bythe dome section 1610 and that the radiation area cannot be thereforeenlarged. Namely, light to be radiated from the light source 1620 in thehorizontal direction (X direction) is reflected by the second reflectionregion 1660. Further, light not enabled to be reflected by neither thefirst reflection region 1640 nor the second reflection region 1660 isnot radiated in the z direction. Thus, the light utilization efficiencylowers.

Further, since the light source 1620 and the lens element 1740 areprepared separately, light from the light source 1620 is transmittedthrough air layer before entering into the incident surface 1630 of lenselement 1740. Therefore, loss of light is generated in that air layer orat the interface. If a stain exists at the interface of the light source1620 and lens element 1740, further loss of light is generated. Stillfurther, due to the separate preparation, a deviation in position mayoccur when being subjected to a physical shock. Therefore, it isdifficult to design an optical system that the light emitting elementand reflection mirror is close to each other. Further, there areproblems that the number of parts or fabrication steps increases andthat variation of precision in fabrication increases.

These problems described above are also included in the LED lightdisclosed in Japanese patent application laid-open No. 2001-93312.

Accordingly, even when a lamp such as an automobile brakelamp-integrated tail lamp is manufactured by using such LED lights, theproper brightness of light source cannot be utilized due to the aboveproblems. Because of this, the lamp appears dark as a whole and lacks adegree of freedom in appearance.

An object of the invention is to provide a light emitting diode and anLED light that have a good appearance based on the low-profile propertyof LED, an enlarged radiation area while using one light emittingelement, and an even brightness in all directions and high externalradiation efficiency, and to provide a high-brightness lamp that isenabled to efficiently use light radiated from a light source.

Another object of the invention is to provide a light emitting unit thatis low-profile, highly efficient and that can be applied to an irregularshape without reducing the efficiency and that can be disposed along aslope while having high external radiation efficiency.

A further object of the invention is to provide a lamp using a lightemitting unit that is enabled to radiate light with an angle widened asmuch as possible while preventing the proper brightness of a lightsource.

A still further object of the invention is to provide a lamp that islow-profile, highly efficient, and that has a large degree of freedom inappearance and an even brightness on the entire surface and that offersa natural feel with glitter.

DISCLOSURE OF INVENTION

To solve the abovementioned problems, a light emitting diode (LED) ofthe invention comprises:

a light emitting element mounted on a power source supply means;

a sealing means of a transparent material to seal the light emittingelement;

a reflection surface that is opposite to an emission surface of thelight emitting element and reflects light emitted from the lightemitting element in a direction orthogonal to the center axis of thelight emitting element or in a direction at a large angle to the centeraxis; and

a side radiation surface that sideward radiates light reflected by thereflection surface in a direction orthogonal to the center axis of thelight emitting element or in a direction at a large angle to the centeraxis.

The LED may have a central radiation surface that is disposed at thecenter of the reflection surface and radiates light emitted from thelight emitting element in a direction nearly parallel to the center axisof the light emitting element.

It is desirable that the central radiation surface has an area smallerthan the emission area of the light emitting element. For example, whenthe central radiation surface is formed circular, it is more desirablethat it is 0.1 mm or more and less than the diagonal length of emissionsurface of the light emitting element. This is because, in the case ofless than 0.1 mm, the radiation effect of central radiation surfacecannot be expected so much and, in the case of exceeding the diagonallength of emission surface, light cannot be efficiently radiated in thehorizontal direction and, when a reflection mirror is provided aroundthe light emitting element, the reflection intensity by reflectionmirror is unbalanced to the radiation intensity from central radiationsurface. The central radiation surface may be formed planar, curved,concave or convex, or into its combination.

The side radiation surface may radiate, in addition to light reflectedby the reflection surface, light directly irradiated from the lightemitting element in a direction orthogonal to the center axis or in adirection at a large angle to the center axis.

The central radiation surface and the reflection surface may be close tothe light emitting element. It is preferable that the distance betweencentral radiation surface and light emitting element is, for example, inthe range of 0.1 mm to 1.5 mm from the element emission surface. It ismore preferable that, when a wire-bonding type light emitting element isused, the central radiation surface is formed in the range of 0.3 mm to1.0 mm from the element emission surface in the center axis direction oflight emitting element. This is because, in the case of using awire-bonding type light emitting element, the wire is upward drawn outand bent and, therefore, if bent excessively, its disconnection may begenerated, and because at least a space of 0.3 mm is needed since thewire is also sealed with the transparent resin. In the case of exceeding1.0 mm, as described later in embodiment 1, in the wire-bonding typelight emitting element, the increment in solid angle of the reflectionsurface decreases and, therefore, its difference decreases as comparedto the case of not forming the central radiation surface.

It is preferable that the outer diameter of the sealing means oftransparent material is 5 to 15 mm. This is because, in the case of lessthan 5 mm, the reflection efficiency of reflection surface cannot beexpected sufficiently and, in the case of exceeding 15 mm, the damage tolight emitting element due to resin stress become significant.

Further, to solve the abovementioned problems, a light emitting diode(LED) of the invention comprises:

a light emitting element mounted on a power source supply means; and

a sealing means of a transparent material to seal the light emittingelement;

wherein the sealing means comprises: a reflection surface that reflectslight emitted from the light emitting element in a direction orthogonalto the center axis of the light emitting element or in a direction at alarge angle to the center axis; and a side radiation surface thatsideward radiates light reflected by the reflection surface; and thereflection surface has a shortest distance from the light emittingelement of less than ½ a radius R of the reflection surface so as toform a proximity optical system.

Further, a light emitting diode (LED) of the invention comprises:

a light emitting element mounted on a power source supply means; and

a sealing means of a transparent material to seal the light emittingelement;

wherein the sealing means comprises: a reflection surface that reflectslight emitted from the light emitting element in a direction orthogonalto the center axis of the light emitting element or in a direction at alarge angle to the center axis; and a side radiation surface thatsideward radiates light reflected by the reflection surface; and thereflection surface is formed such that its radius R is greater than aheight H from the emission surface of the light emitting element to anedge of the reflection surface in the center axis direction of the lightemitting element so as to form a proximity optical system.

It is desirable that, in the LED, the light emitting element has aradiation intensity I(θ) represented by: I(θ)=k·cos θ+(1−k)·sin θ at anemission angle θ of emitted light to the center axis direction, where kis a constant to be determined by a radiation intensity according to theemission angle θ of the light emitting element, and k≦0.8 is satisfied.

It is preferable that, in the LED, the light emitting element comprisesa transparent substrate to have a light transmitting property to lightemitted therefrom.

It is desirable that, in the LED, the sealing means comprises a lightdiffusing material to cover the light emitting element.

In the LED, the light diffusing material may be a phosphor.

Further, to solve the abovementioned problems, a light emitting diode(LED) of the invention comprises:

a light emitting element that is mounted on a power source supply meansand sealed with a sealing member of a transparent material; and

the sealing member that comprises a reflection surface and a sidereflection surface formed thereon, the reflection surface reflectinglight radiated from an emission surface of the light emitting elementand the side radiation surface radiating reflected light from thereflection surface and direct light form the light emitting element;

wherein the reflection surface has a solid angle of 2 π{1−cos θc} orgreater to the light emitting element, where θc is a critical angle ofthe transparent material, and the side radiation surface is formed suchthat an incident angle of reflected light from the reflection surfaceand an incident angle of direct light from the light emitting elementare smaller than θc so as to externally radiate light emitted from thelight emitting element.

The reflection surface may have a shape to be formed by rotating, aroundthe center axis of the light emitting element, part of a linerepresented by Z=f(X) in a plane formed between the center axis (Z-axis)of the light emitting element and an X-axis orthogonal to the Z-axis,and the Z=f(X) satisfies {d²f(X)/dX²}<0. If the Z=f(X) satisfies{d²f(X)/dX²}<0, even when a large solid angle to the light emittingelement is taken in the case of the reflection surface having the samediameter, then an incident angle to the side radiation surface can besmall.

The reflection surface may have a shape to be formed by rotating, aroundthe center axis of the light emitting element, part of ellipse, parabolaor hyperbola with a focal point at the light emitting element or itsvicinity. These are typical forms, practically available, of curvesrepresented by {d²f(X)/dX²}<0.

The side radiation surface may have a slope to be inclined to the lightemitting element.

The side radiation surface may compose part of a spherical surfacecentered at the light emitting element.

Further, to solve the abovementioned problems, a light emitting diode(LED) of the invention comprises:

the lead frame that is protruded out of the transparent resin whilebeing bent under its mount surface from the vicinity of a mount positionof the light emitting element so as to reduce part of the lead framesealed with the transparent resin as much as possible.

The LED may comprise the lead frame that comprises part sealed with thetransparent resin that has a wide area sufficient to widely conduct anddisperse heat generated from the light emitting element.

The lead frame may be of a material with a high thermal conductivity. Itis desirable that it is of a conductive material with a thermalconductivity of 300 W/m·k or more.

Further, a light emitting diode of the invention may comprise:

a light emitting element to emit light;

a lead frame to supply electric power to the light emitting elementmounted thereon; and

a transparent resin to seal the light emitting element and the leadframe;

wherein the transparent resin comprises: a first transparent resin toseal the light emitting element and part of the lead frame; and a secondtransparent resin disposed in contact with and around the side of thefirst transparent resin.

Further, to solve the abovementioned problems, a light emitting diode(LED) of the invention comprises:

an light emitting section that comprises a two-dimensional directionreflection surface to reflect light emitted from a light emittingelement embedded in a transparent material at least in a two-dimensionaldirection; and

a reflector section that is optically connected at least around in thetwo-dimensional direction of the light emitting section and comprises areflection surface formed extending from the two-dimensional directionreflection surface.

The reflector section may be formed low-profile and additionally reflectlight reaching a surface opposite to the reflection surface of lightradiated from the light emitting section.

The reflector may comprise a stepwise reflection surface that isopposite to the reflection surface and, in a direction perpendicular tothe two-dimensional direction, reflects light being reflected by thetwo-dimensional direction reflection surface and the reflection surfacein the two-dimensional direction.

The two-dimensional direction reflection surface of the light emittingsection may have a shape to be formed by rotating, around aperpendicular axis passing through the center of an emission surface ofthe light emitting element, part of ellipse, parabola, hyperbola or itsapproximated curve with a focal point at the light emitting element orits vicinity.

A light emitting diode of the invention may comprise:

a light source section that comprises a circular cone portion that isopposite to an emission surface of a light emitting element embedded andis formed protruding outside; and

a reflection section that comprises a two-dimensional directionreflection surface that is connected at least to the circular coneportion and reflects light radiated from the light source section atleast in a two-dimensional plane direction.

Further, to solve the abovementioned problems, an LED light of theinvention comprises:

an LED; and

a reflection mirror disposed around the LED;

wherein the LED comprises: a light emitting element mounted on a powersource supply means; a sealing means of a transparent material to sealthe light emitting element; a reflection surface that is opposite to anemission surface of the light emitting element and reflects lightemitted from the light emitting element in a direction orthogonal to thecenter axis of the light emitting element or in a direction at a largeangle to the center axis; and a side radiation surface that sidewardradiates light reflected by the reflection surface in a directionorthogonal to the center axis of the light emitting element or in adirection at a large angle to the center axis.

It is desirable that the LED further comprises a central radiationsurface that is disposed at the center of the reflection surface andradiates light emitted from the light emitting element in a directionnearly parallel to the center axis of the light emitting element.

An LED light of the invention may comprise:

an LED that comprises: a light emitting element mounted on a powersource supply means; and a sealing means of a transparent material toseal the light emitting element; wherein the sealing means comprises: areflection surface that reflects light emitted from the light emittingelement in a direction orthogonal to the center axis of the lightemitting element or in a direction at a large angle to the center axis;and a side radiation surface that sideward radiates light reflected bythe reflection surface; and the reflection surface has a shortestdistance from the light emitting element of less than ½ a radius R ofthe reflection surface so as to form a proximity optical system; and

a reflection mirror that reflects light radiated from the LED.

The light emitting element may have a radiation intensity I(θ)represented by: I(θ)=k·cos θ+(1−k)·sin θ at an emission angle θ ofemitted light to the center axis direction, where k is a constant to bedetermined by a radiation intensity according to the emission angle θ ofthe light emitting element, and k≦0.8 is satisfied.

An LED light of the invention may comprise:

an LED that comprises: a light emitting element that is mounted on apower source supply means and sealed with a sealing member of atransparent material; and the sealing member that comprises a reflectionsurface and a side reflection surface formed thereon, the reflectionsurface reflecting light radiated from an emission surface of the lightemitting element and the side radiation surface radiating reflectedlight from the reflection surface and direct light form the lightemitting element; wherein the reflection surface has a solid angle of2π{1−cos θc} or greater to the light emitting element, where θc is acritical angle of the transparent material, and the side radiationsurface is formed such that an incident angle of reflected light fromthe reflection surface and an incident angle of direct light from thelight emitting element are smaller than θc so as to externally radiatelight emitted from the light emitting element; and

a reflection mirror that reflects light radiated from the LED.

An LED light of the invention may comprise:

an LED that comprises: a light emitting element to emit light; a leadframe to supply electric power to the light emitting element mountedthereon; and a transparent resin to seal the light emitting element andthe lead frame; wherein the lead frame is protruded out of thetransparent resin while being bent under its mount surface from thevicinity of a mount position of the light emitting element; and

a reflection mirror that reflects light radiated from the LED.

An LED light of the invention may comprise:

an LED that comprises: a light emitting element to emit light; a leadframe to supply electric power to the light emitting element mountedthereon; and a transparent resin to seal the light emitting element andthe lead frame; wherein the lead frame comprises part sealed with thetransparent resin that has a wide area sufficient to widely conduct anddisperse heat generated from the light emitting element; and

a reflection mirror that reflects light radiated from the LED.

An LED light of the invention may comprise:

a light emitting element;

a first reflection mirror that is formed on the light emitting elementand reflects light emitted from the light emitting element in the sidedirection; and

a second reflection mirror that upward reflects light from the firstreflection mirror.

A third reflection mirror may be disposed inside the second reflectionmirror and upward reflects light sideward emitted from the lightemitting element.

The first reflection mirror and the second reflection mirror may beformed into one optical member.

The second reflection mirror may be in the shape of a polygon or itssimilar form when viewed from upward.

The light emitting element may be mounted on a circuit board on a metalplate.

Further, to solve the abovementioned problems, a light emitting unit ofthe invention comprises:

a light source that comprises: a light emitting element mounted on apower source supply means; a sealing means of a transparent material toseal the light emitting element; a first reflection surface that isopposite to an emission surface of the light emitting element andreflects light emitted from the light emitting element in a directionorthogonal to the center axis of the light emitting element or in adirection at a large angle to the center axis; and a side radiationsurface that sideward radiates light reflected by the first reflectionsurface in a direction orthogonal to the center axis of the lightemitting element or in a direction at a large angle to the center axis;and

a reflector that comprises a plurality of second reflection surfaces toreflect the light radiated from the side radiation surface in apredetermined radiation direction.

It is preferable that, in the light emitting unit, the light sourcefurther comprises a central radiation surface that is disposed at thecenter of the first reflection surface and radiates light emitted fromthe light emitting element in a direction nearly parallel to the centeraxis of the light emitting element.

It is preferable that, in the light emitting unit, the first reflectionsurface is formed close to the light emitting unit so as to increase alight receiving angle (solid angle) of the upper reflection surface.

It is preferable that, in the light emitting unit, the light source isdisplaced from the center and the position of optical control surfacesneighboring in the circumference direction is different from each otherin the radius direction.

In the light emitting unit, the reflector may reflect the light, as thepredetermined radiation direction, in a direction with a predeterminedinclination to the center axis of the light emitting element by theplurality of second reflection surfaces.

In the light emitting unit, the reflector may be mounted on an inclinedsection.

In the light emitting unit, the plurality of second reflection surfaceseach may have an optical control surface that its angle and directionare set to allow reflected light to be reflected in a same direction.

Further, to solve the abovementioned problems, a lamp of the inventioncomprises:

a plurality of light emitting units each of which comprises: a lightsource that comprises an optical system to radiate light emitted from alight emitting element in a direction orthogonal to the center axis ofthe light emitting element or in a direction at a large angle to thecenter axis; and a reflector that comprises a plurality of secondreflection surfaces to, in a predetermined direction, reflect the lightradiated from the light source in the direction orthogonal to the centeraxis of the light emitting element or in the direction at the largeangle to the center axis;

wherein the plurality of light emitting units are disposed in apredetermined arrangement.

In the lamp, the light source may have a lead frame fixed on aboarddisposed on the back side of a housing, and its fixing positioncorresponds to a penetration hole of the reflection mirror.

In the lamp, the board may be, at the fixing position, provided with aconcave member into which the lead frame is inserted.

In the lamp, the light source may comprise: a light emitting elementmounted on a power source supply means; a sealing means of a transparentmaterial to seal the light emitting element; a first reflection surfacethat is opposite to an emission surface of the light emitting elementand reflects light emitted from the light emitting element in adirection orthogonal to the center axis of the light emitting element orin a direction at a large angle to the center axis; and a side radiationsurface that sideward radiates light reflected by the first reflectionsurface in a direction orthogonal to the center axis of the lightemitting element or in a direction at a large angle to the center axis.

In the lamp, the light source may comprise a plurality of LED's that arearranged radially such that an intersection point of the center axes ofthe plurality of LED's is a point on a same plane.

In the lamp, the plurality of light emitting units may be disposed suchthat part of the reflector of the neighboring light emitting units isoverlapped.

In the lamp, the plurality of light emitting units may include aplurality of light emitting units that are arranged at multiple stagesor in multiple rows, and the light emitting units at each stage includea plurality of light emitting units arranged linearly.

In the lamp, the plurality of light emitting units may be arrangedthrough a partition plate to separate the plurality of light emittingunits arranged linearly.

In the lamp, the plurality of light emitting units may have a lightreflection finish on at least part of the circumference of the lightemitting unit or the partition plate.

In the lamp, the plurality of light emitting units may be disposed suchthat the neighboring light emitting units are arranged at differentstages in the center axis direction.

In the lamp, the plurality of light emitting units may be composed suchthat a plurality of reflection surfaces are concentric disposed aroundthe light source.

In the lamp, the plurality of reflection surfaces may be formed nearlyplanar.

Herein, “angle” means an angle of the light source to the lightradiation surface and “direction” means an angle of the light source tothe light radiation direction.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross sectional view showing a light emitting diode inembodiment 1A of the invention.

FIG. 2 is an enlarged cross sectional view showing part of the lightemitting diode in embodiment 1A of the invention.

FIG. 3 is graphs showing the relationship between a distance h from theupper surface of a light emitting element to a central radiation surfaceand an increment of solid angle in the light emitting diode shown inFIG. 2, wherein (a) is the case of a diameter in transparent resin of 5mm, (b) of 7.5 mm and (c) of 15 mm.

FIG. 4 is cross sectional views showing shape examples of the centralradiation surface of the light emitting diode in embodiment 1A of theinvention, wherein (a) is planar, (b) is curved only at the boundary ofcentral radiation surface and upper reflection surface, (c) is curved onthe entire central radiation surface, (d) is concaved and (e) isconvexed.

FIG. 5 is a graph illustrating another example of upper reflectionsurface of the light emitting diode in embodiment 1A of the invention.

FIG. 6 is a cross sectional view showing another example of the lightemitting diode in embodiment 1A of the invention.

FIG. 7 is a cross sectional view showing another example of the lightemitting diode in embodiment 1A of the invention.

FIG. 8 is a cross sectional view showing another example of the lightemitting diode in embodiment 1A of the invention.

FIG. 9 is a cross sectional view showing a method (transfer molding) ofmaking the light emitting diode in embodiment 1A of the invention.

FIG. 10 is a cross sectional view showing a method (casting mold) ofmaking the light emitting diode in embodiment 1A of the invention.

FIG. 11( a) is a plain view showing an LED light in embodiment 1B of theinvention, (b) is a cross sectional view cut along the line A-A in (a),and (c) is an enlarged cross sectional view showing part P in (b).

FIG. 12 is a cross sectional view showing an LED as a light source ofthe LED light in embodiment 1B of the invention.

FIG. 13 is a plain view showing an integrated LED light to cover apredetermined area, wherein a plurality of the LED lights in embodiment1B of the invention are cut into rectangular form.

FIG. 14 is a cross sectional view showing a first modification of LED asa light source of the LED light in embodiment 1B of the invention.

FIG. 15 is a cross sectional view showing a second modification of LEDas a light source of the LED light in embodiment 1B of the invention.

FIG. 16 is a cross sectional view showing a third modification of LED asa light source of the LED light in embodiment 1B of the invention.

FIG. 17 is a cross sectional view showing a fourth modification of LEDas a light source of the LED light in embodiment 1B of the invention.

FIG. 18( a) is a plain view showing a fifth modification of the LEDlight in embodiment 1B of the invention, (b) is a cross sectional viewcut along the line B-B in (a), (c) is a cross sectional view cut alongthe line C-C in (a), and (d) is a cross sectional view cut along theline D-D in (a).

FIG. 19( a) is a plain view showing a sixth modification of the LEDlight in embodiment 1B of the invention, (b) is a cross sectional viewcut along the line E-E in (a), and (c) is a cross sectional view cutalong the line F-F in (a).

FIG. 20 is a cross sectional view showing an LED used for an LED lightin embodiment 1C of the invention.

FIG. 21 is a cross sectional view showing an LED light in embodiment 1Dof the invention.

FIG. 22 is a cross sectional view showing an LED light in embodiment 1Eof the invention.

FIG. 23 is a cross sectional view showing an LED light in embodiment 1Fof the invention.

FIG. 24( a) is a plain view showing an LED light in embodiment 1G of theinvention, and (b) is a cross sectional view cut along the line G-G in(a).

FIG. 25( a) is a plain view showing an LED light using an LED inembodiment 2A of the invention, (b) is a cross sectional view cut alongthe line A-A in (a), and (c) is an enlarged cross sectional view showingpart P of (b).

FIG. 26( a) is a cross sectional view showing an LED used for the LEDlight in embodiment 2A of the invention, (b) is a plain view thereof,and (c) is a side view showing the size of LED.

FIG. 27 is a side view showing a light emitting element in embodiment 2Aof the invention.

FIG. 28 is an illustration showing light radiated from an upper surfaceand a side surface of the light emitting element in embodiment 2A of theinvention.

FIG. 29 shows light distribution characteristic curves in embodiment 2Aof the invention, wherein (a) is an illustration showing an angle toZ-axis of light emitting element, (b) is a characteristic diagramshowing a change in radiation intensity in case of k=1, (c) is acharacteristic diagram showing a change in radiation intensity in caseof k=0.8, and (d) is a characteristic diagram showing a change inradiation intensity in case of k=0.6.

FIG. 30 is a graph showing a relationship between effective radiationefficiency ratio and a deviation in X-axis direction in embodiment 2A ofthe invention.

FIGS. 31( a) and (b) are illustrations showing observation conditions oflight amount radiated from LED.

FIG. 32 shows a deviation in total light amount in effective radiationrange of LED in embodiment 2A of the invention, wherein (a) is acharacteristic diagram showing a deviation in total light amount ineffective radiation range of LED using a light emitting element with atop light distribution characteristic of 100%, and (b) is acharacteristic diagram showing a deviation in total light amount ineffective radiation range of LED using a light emitting element with atop light distribution characteristic of 80%.

FIG. 33( a) is a plain view showing an LED light using an LED inembodiment 2B of the invention, and (b) is a cross sectional viewshowing the vicinity of a light emitting element in (a).

FIG. 34 is a characteristic diagram showing a deviation in total lightamount in effective radiation range of LED using a light emittingelement with a top light distribution characteristic of 60% (k=0.6) inembodiment 2B of the invention.

FIG. 35( a) is a plain view showing an LED light using an LED inembodiment 2C of the invention, and (b) is a cross sectional viewshowing the vicinity of a light emitting element in (a).

FIG. 36 is a cross sectional view showing an LED light using an LED inembodiment 2D of the invention.

FIG. 37 shows an LED in embodiment 3A of the invention, wherein (a) is across sectional view thereof, and (b) is a plain view thereof.

FIG. 38 is a graph showing a relationship between incident angle andtransmittance in LED.

FIG. 39 is a cross sectional view showing a light emitting element usedfor the LED in embodiment 3A of the invention.

FIGS. 40( a), (b) and (c) are characteristic diagrams showing a lightintensity distribution, a light flux distribution, and a light fluxintegration in a standard light emitting element (in case of 20 mil and14 mil).

FIG. 41 is a cross sectional view showing another reflection surfaceformed on the LED in embodiment 3A of the invention.

FIG. 42( a) is a plain view showing a first modification of the LED inembodiment 3A of the invention, and (b) is a cross sectional viewthereof.

FIG. 43 is a plain view showing a second modification of the LED inembodiment 3A of the invention.

FIG. 44 is a plain view showing a third modification of the LED inembodiment 3A of the invention.

FIG. 45 is a plain view showing a fourth modification of the LED inembodiment 3A of the invention.

FIG. 46 is a plain view showing a seventh modification of the LED inembodiment 3A of the invention.

FIG. 47( a) is a plain view showing an LED light using an LED inembodiment 3B of the invention, (b) is a cross sectional view cut alongthe line A-A in (a), and (c) is an enlarged cross sectional view showingpart P in (b).

FIG. 48 shows a dimensional relationship between LED and secondreflection mirror in an LED light using the LED in embodiment 3B of theinvention, wherein (a) is the case of using LED with a small diameterand (b) is the case of using LED with a large diameter.

FIG. 49 is a cross sectional view showing an LED used for a firstmodification of the LED light in embodiment 3B of the invention.

FIG. 50 is a cross sectional view showing a second modification of theLED light in embodiment 3B of the invention.

FIG. 51 is a diagram showing a light distribution characteristic of LEDused for the second modification of LED light.

FIG. 52( a) is a plain view showing an LED light using an LED inembodiment 4A of the invention, (b) is a cross sectional view cut alongthe line A-A in (a), and (c) is an enlarged cross sectional view showingpart P in (b).

FIG. 53 is a cross sectional view showing the LED as a light source ofthe LED light in embodiment 4A of the invention.

FIG. 54 is a plain view showing the LED in embodiment 4A of theinvention.

FIG. 55 is a cross sectional view showing a light emitting element usedfor the LED in embodiment 4A of the invention.

FIG. 56 is a cross sectional view showing the LED with lead framesprojecting in horizontal direction.

FIG. 57( a) is a plain view showing the LED with lead frames of widearea, (b) is a cross sectional view of (a), and (c) is a cross sectionalview in the case of having fins in (b).

FIG. 58 is a cross sectional view showing an LED as a light source of anLED light in embodiment 5A of the invention.

FIG. 59 is a plain view showing the LED in embodiment 5A of theinvention.

FIG. 60 is a cross sectional view showing a modification of LED as alight source of the LED light in embodiment 5A of the invention.

FIG. 61( a) is a plain view showing an LED in embodiment 6A of theinvention, and (b) is a cross sectional view thereof.

FIG. 62 is an illustration showing a two-dimensional radiationcharacteristic of the LED in embodiment 6A of the invention.

FIG. 63 is a cross sectional view showing a lamp using the LED inembodiment 6A of the invention.

FIG. 64 is a cross sectional view showing an LED in embodiment 6B of theinvention.

FIG. 65 is a cross sectional view showing an LED in embodiment 6C of theinvention.

FIG. 66( a) is a plain view showing an LED in embodiment 6D of theinvention, and (b) is a cross sectional view thereof.

FIG. 67 is a cross sectional view showing an LED in embodiment 6E of theinvention.

FIG. 68 is a plain view showing a light emitting unit in embodiment 7Aof the invention.

FIG. 69 is a plain view showing an LED as a light source of the lightemitting unit in embodiment 7A of the invention.

FIG. 70 is a cross sectional view showing the LED as a light source ofthe light emitting unit in embodiment 7A of the invention.

FIG. 71 is a plain view showing a light emitting unit in embodiment 7Bof the invention.

FIG. 72 is a plain view showing a light emitting unit in embodiment 7Cof the invention and a distribution of light emitting points in thelight emitting unit.

FIG. 73 is a cross sectional view showing the light emitting unit inembodiment 7C to be cut along the line A-A in FIG. 72.

FIG. 74 is a cross sectional view showing a light source of a lightemitting unit in embodiment 7D of the invention.

FIG. 75 is a cross sectional view showing a light source of a lightemitting unit in embodiment 7E of the invention.

FIG. 76 is a plain view showing a light source of a light emitting unitin embodiment 7F of the invention.

FIG. 77 is a plain view showing a light source of a light emitting unitin embodiment 7G of the invention.

FIG. 78 is a perspective view showing a lamp in embodiment 7H of theinvention.

FIG. 79 is an enlarged perspective view showing part of a reflectionsurface of a light emitting unit in embodiment 7I of the invention.

FIG. 80 is a plain view showing the light emitting unit in embodiment 7Iof the invention.

FIG. 81 is a cross sectional view showing a light emitting unit inembodiment 7J of the invention.

FIG. 82( a) is a plain view showing an LED used as a light source of thelight emitting unit in embodiment 7J of the invention, and (b) is across sectional view thereof.

FIG. 83 is a cross sectional view showing the light emitting unit inembodiment 7J of the invention to be attached to a car body.

FIG. 84 is a cross sectional view showing a light emitting unit inembodiment 7K of the invention.

FIG. 85 is a plain view showing the light emitting unit in embodiment 7Lof the invention.

FIG. 86 is a perspective view showing an automobile combination lamp inembodiment 7M of the invention.

FIG. 87 is a cross sectional view cut along the line C-C in FIG. 86.

FIG. 88 is a perspective view showing an LED mounting board of thecombination lamp in FIG. 87.

FIG. 89 is an enlarged perspective view showing an LED mounting part ofthe LED mounting board in FIG. 88.

FIG. 90 is a front view showing an automobile combination lamp inembodiment 7N of the invention.

FIG. 91 is a cross sectional view cut along the line J-J in FIG. 90.

FIG. 92 is a cross sectional view showing an automobile combination lampin embodiment 7P of the invention.

FIG. 93( a) is a plain view showing a lamp in embodiment 8A of theinvention, and (b) is a cross sectional view thereof.

FIG. 94( a) is a cross sectional view cut along the line A-A to show asegment of the lamp in embodiment 8A of the invention, and (b) is across sectional view cut along the line B-B.

FIG. 95( a) is a cross sectional view cut along the line A-A to show asegment of a modification of the lamp in embodiment 8A of the invention,and (b) is a cross sectional view cut along the line B-B.

FIG. 96( a) is a cross sectional view cut along the line A-A to show asegment of another modification of the lamp in embodiment 8A of theinvention, and (b) is a cross sectional view cut along the line B-B.

FIG. 97 is a plain view showing a lamp in embodiment 8B of theinvention.

FIG. 98 is a plain view showing a lamp in embodiment 8C of theinvention.

FIG. 99 is a plain view showing a lamp in embodiment 8D of theinvention.

FIG. 100 is a cross sectional view showing a lamp in embodiment 8E ofthe invention.

FIG. 101( a) is a plain view showing a radiation light source used for alamp in embodiment 8F of the invention, (b) is a plain view showing alens type LED to compose the radiation light source, (c) is a side viewthereof, and (d) is a front view thereof.

FIG. 102( a) is a plain view showing a radiation light source used for alamp in embodiment 8G of the invention, (b) is a plain view showing areflection type LED to compose the radiation light source, and (c) is across sectional view thereof.

FIG. 103 is a cross sectional view showing an example of theconventional LED light.

FIG. 104 shows another example of the conventional LED light, wherein(a) is a cross sectional view showing the LED light with a light sourcecentered, and (b) is a perspective view showing part of the LED light.

FIG. 105 shows another example of the conventional LED light, wherein(a) is a cross sectional view showing the LED light with a light sourcecentered, and (b) is a cross sectional view cut along the line K-K in(a).

BEST MODES FOR CARRYING OUT THE INVENTION

The embodiments of the invention will be explained below with referenceto the drawings.

Embodiment 1A

At first, a light emitting diode in embodiment 1A of the invention willbe explained with reference to FIG. 1 and FIG. 2. As shown in FIG. 1,the light emitting diode 10 has a light emitting element 1 that hasdimensions of 400×400 μm and is mounted through Ag paste (not shown) ona lead frame 2 a. The light emitting element 1 has an electrode, whichhas a diameter of 0.1 mm and is formed on the center of emissionsurface, and a gold wire ball (not shown) formed thereon that areelectrically connected through a wire 3 with a diameter of 30 μm to alead 2 b with an opposite polarity. These are sealed with transparentresin 4 and the optical surface is molded.

As shown in FIG. 2, the optical surface is composed of a centralradiation surface 4 a, an upper reflection surface 4 b and a sideradiation surface 4 c. The central radiation surface 4 a is h=0.5 mmabove the upper surface of light emitting element 1 and is in the shapeof a cylinder with a diameter of Wc=0.3 mm. The upper reflection surface4 b is formed by, around a z-axis, rotating a parabola that has a focalpoint at the center of upper surface of light emitting element 1,passing through the end of central radiation surface 4 a, and having asymmetry axis perpendicular to the z-axis. The side radiation surface 4c is formed as a cylindrical surface that is nearly perpendicular to thez-axis and is slightly tapered to facilitate the release from a die. Thetransparent resin 4 composed of the central radiation surface 4 a, upperreflection surface 4 b and side radiation surface 4 c has an outerdiameter of Wm=7.5 mm.

In order to have a larger sold angle when the transparent resin 4 is setto be a predetermined outer diameter, the upper reflection surface mayhave a shape to be formed by rotating a parabola with the same focalposition and a smaller homothetic ratio (for example, 4 b′ to 4 b).However, in the case of a wire bonding type light emitting element, awire space is needed over the light emitting element 1 as shown inFIG. 1. Namely, the light emitting element 1 has an electrode(n-electrode or p-electrode) on its upper surface and the wire 3 isbonded thereto. A space of at least 0.3 mm (0.2 mm for wire and 0.1 mmfor seal) is required since the wire 3 to be drawn upward and bent ininstallation may be broken when being extremely bent and it has to besealed with transparent resin. Therefore, the optical surface isprovided with the upper reflection surface 4 b with a homothetic ratiosmaller than a virtual upper reflection surface 4 b′ indicated by adotted curve and with the central radiation surface 4 a.

Due to the optical surface thus composed, light heading to the Z-axisdirection can be radiated from the center of LED package and thereflection efficiency in a direction perpendicular to the Z-axis can beenhanced. Namely, in FIG. 2, provided that the center of emissionsurface of light emitting element 1 is point 0 (zero), an angle to theZ-axis of a direction from the point 0 edge to the edge of upperreflection surface is θ₀=60 degrees in the case of dotted curve 4 b′ andθ₁=65 degrees in the case of solid curve 4 b. These angles correspondto, as solid angle, A₀=3.1 strad and A₁=3.6 strad to the point 0 (inboth cases, the upper reflection surface has a shape to be formed byrotating, around the Z-axis, a parabola with a symmetry axisperpendicular to the Z-axis). On the other hand, an angle θ₂ to theZ-axis of a direction from the point 0 to the edge of central radiationsurface is 17 degrees and a solid angle to the point 0 is A₂=0.25 strad.Namely, by providing the optical surface indicated by the solid curve,although at part of the central radiation surface the solid angle isdecreased by A₂=0.25 strad since reflection to a direction nearlyperpendicular to the Z-axis is not obtained, an increment of solid anglebecomes A₁−A₀=0.5 by changing 4 b′ into 4 b. Thus, an increment of solidangle is eventually (A₁−A₀)−A₂=0.25 when the decrement is subtracted. Asolid-angle increment ratio of upper reflection surface to light sourceis 0.25/π, i.e., increased by about 10%. Accordingly, the radiationefficiency to a direction perpendicular to the Z-axis can be enhanced.

Although in embodiment 1A the light emitting diode 10 is exemplifiedthat the central radiation surface with a diameter of 0.3 mm is providedthe light emitting element 1 of 400 μm square, the other dimensions maybe used other than the above. However, if the central radiation surface4 a is extremely expanded, more light will be radiated from the uppersurface and the radiation efficiency to a direction perpendicular to theZ-axis will lower. Thereby, the original concept will be spoiled.Therefore, it is desired that the central radiation surface 4 a islimited to about the dimensions of emission surface of light emittingelement or smaller. Further, although in embodiment 1A the distance hbetween the upper emission surface of light emitting element 1 and thecentral radiation surface is 0.5 mm and the diameter of transparentresin 4 is 7.5 mm, suitable values other than the above may be used inthe range the effect can be obtained.

FIG. 3( a), (b) and (c) show, as a function of h, a solid-angleincrement of upper reflection surface to point 0 in the case of forminga central radiation surface (4 a and 4 b) in comparison with the case ofnot forming a central radiation surface (4 b′ in FIG. 2) while settingthe diameter of transparent resin to be 5 mm, 7.5 mm and 15 mm,respectively. Referring to FIG. 3( b), in the case of transparent resinwith a diameter of 7.5 mm, the solid-angle increment can be maximum ath=0.6 mm as compared to the case of not forming the central radiationsurface. If h increases greater than this, a difference to the case ofnot forming the central radiation surface decreases and the solid-angleincrement of upper reflection surface lowers. On the other hand, if hdecreases, the solid-angle increment of upper reflection surface lowerssince a solid angle occupied by the central radiation surface increases.Even when the diameter of transparent resin is changed, the sametendency is observed. Such a tendency is significant in the case oftransparent resin with a small diameter rather than in the case oftransparent resin with a large diameter. However, if the diameter isless than 15 mm, the advantageous effect in solid-angle increment can beobtained by providing the central radiation surface. In view of theabove results, it is desirable to have h=0.3 to 1.0 mm and a diameter oftransparent resin of 5 to 15 mm.

In FIG. 2 and FIG. 3, when the central radiation surface 4 a is closedto the emission surface of light emitting element 1 like the case oftransparent resin with a diameter of 15 mm and h=0.3 mm, the edge angle(θ₂) of central radiation surface 4 a and its solid angle (A₂) areincreased theoretically. Therefore, the solid-angle increment((A₁−A₀)−A₂) of upper reflection surface 4 b to point 0 in the case offorming a central radiation surface in comparison with the case of notforming a central radiation surface becomes negative as shown in FIG. 3(c). However, in fact, since the light emitting element under the centralradiation surface 4 a is provided with the electrode with a diameter of0.1 mm formed on the center of its emission surface and with the goldwire ball which are all non-emission parts, the amount of light to beexternally radiated from the central radiation surface does notincrease. Therefore, the influence of negative solid-angle incrementcaused by A₂ is exactly weak and the radiation efficiency to a directionnearly perpendicular to the Z-axis can be enhanced due to an increment(A₁−A₀).

The central radiation surface 4 a is not limited to planar as shown inFIG. 4( a) and may be curved only at the boundary of central radiationsurface 4 a and upper reflection surface 4 b as shown in FIG. 4( b),curved over the entire central radiation surface 4 a as shown in FIG. 4(c), concave as shown in FIG. (d), or convex as shown in FIG. 4( d).

The upper reflection surface 4 b may have a shape to be formed not onlyby rotating a parabola with a focal point at the center of upper surfaceof light emitting element and with a symmetry axis on the X-axis butalso by rotating a parabola that has a symmetry axis in a directioninclined from the X-axis as shown in FIG. 5. Further, it may have ashape to be formed by rotating an ellipse with long focus or hyperbolaor the like other than parabolas.

The light emitting element may be provided with the electrode formed atthe periphery of upper surface other than at the center of uppersurface. In this case, the limitation of dimension h as described abovedoes not occur in view of wire space. However, if disposed too close,the solid angle (to he light emitting element) of the central radiationsurface 4 a becomes significantly large at the upper reflection surface4 b. In the resin sealing, if the gap is narrow, the resin may be notfilled therein and the light emitting element may be subjected to anunnatural stress even after the sealing. Therefore, it is desirable thata predetermined space is provided between the upper emission surface oflight emitting element 1 and the central radiation surface.

The package form is not limited to that shown in FIG. 1 and may be suchthat copper-foil patterns 5 a, 5 b are formed on a metal board 7 throughan insulation layer 6 and the light emitting element 1 is formed thereonas shown in FIG. 6 or such that leads 8 a, 8 b are drawn below as shownin FIG. 7.

The light emitting element may be coated with phosphor. In this case, asshown in FIG. 8, a light source 9 can be such that the light emittingelement 1 is sealed with a coat including phosphor 12.

The light emitting diode 10 in embodiment 1A can be fabricated by using,e.g., the transfer molding. The transfer molding will be explained belowreferring to FIG. 9. At first, the light emitting element 1 is face-upbonded to the lead frame 2 a being formed by pressing. Then, an Albonding pad of the light emitting element 1 is electrically connectedthrough a wire 3 to the lead frame 2 b. Then, the lead frame 2 a, 2 bwith the light emitting element 1 mounted is positioned on a die 20B,and sandwiched by a descending die 20A to keep the position of leadframes and die. Then, transparent epoxy 4 including a release agent isinjected into the die. Then, the transparent epoxy 4 is cured under theconditions of 160° C. and 5 min. Then, the dies 20A, 20B are separatedvertically and the light emitting diode 10 with transparent epoxy curedis taken out. In thus fabricating the light emitting diode 10 by thetransfer molding, the transparent resin 4 is injected into interiors20C, 20D of the die while sandwiching the lead frames 2 a, 2 b.Therefore, the positioning between the light emitting element 1 andoptical surface can be performed at a high precision of ±0.1 mm.Thereby, dispersion in light distribution characteristic due to anindividual difference of the light emitting diode 10 using the proximityoptical system can be prevented.

The light emitting diode 10 can be also fabricated by the casting mold.The casting mold will be explained below referring to FIG. 10. At first,lead frames 21 a, 21 b are punched out by pressing. At that time, thelead frames 21 a, 21 b are kept connected with a lead at its multipleends without being separated. Then, the lead-connected ends are securedby a supporting member. Then, the light emitting element 1 is face-upbonded to the tip of lead frame 21 b. Then, an Al bonding pad of thelight emitting element 1 is electrically connected through a wire 3 tothe lead frame 21 a. Then, the lead frames 21 a, 21 b are moved above acasting 20F for molding. Then, resin 4 is injected into the casting 20F.Then, the lead frames 21 a, 21 b are soaked in the casting 20F withresin 4 injected. Then, a space 20E with the casting 20F and lead frames21 a, 21 b disposed is vacuumed to deaerate the resin 4. Then, the resin4 is cured under the conditions of 120° C. and 60 min. Then, the lightemitting diode 4 with resin 4 cured is taken out from the casting 20F.In the casting mold, since the tip (free end) of lead frames 21 a, 21 bis not restrained by the casting, precision in positioning between thelight emitting element 1 and optical surface lowers to ±0.2 mm ascompared to that in the transfer molding. However, by curing thetransparent resin 4 for long hours, unevenness in thermal stress isreduced and the lead frames 21 a, 21 b are not likely to be releasedfrom the transparent resin 4. Meanwhile, by choosing the fabricationprocess management and the light distribution characteristic of lightemitting element 1, the light distribution characteristic can bestabilized.

Embodiment 1B

Embodiment 1B of the invention will be explained with reference to FIG.11 to FIG. 19.

As shown in FIG. 11, an LED light 31 in embodiment 1B of the inventionis constructed such that the light emitting diode (LED) in embodiment 1Ais, as a light source, mounted at the center of a circular body and issurrounded by a reflection mirror 33, as a second reflection mirror,which is formed concentric and stepwise. Herein, the center axis oflight emitting element is defined as a Z-axis, and its origin is at theupper surface of light emitting element and an X-axis and a Y-axisintersect at right angles at the origin. These definitions are appliedto modifications and embodiments described below as well.

As shown in FIG. 11( c), a reflection surface 33 a of the reflectionmirror 33 is about 45 degrees inclined to the X-Y plane. The reflectionmirror 33 is made by molding acrylic resin and then being formed of thereflection surface by aluminum evaporation.

Then, the LED 32 will be explained below with reference to FIG. 12. Asshown in FIG. 12, a light emitting element 36 is mounted on the tip of alead plate 35 a with larger area of a pair of lead plates 35 a, 35 b.The upper-surface electrode of light emitting element 36 is electricallyconnected to the tip of lead frame 35 b through a wire 37. The tipportion of lead plates 35 a, 35 b, light emitting element 36 and wire 37as electric system are set in a die for resin mold, and they are sealedwith transparent epoxy resin 38 to have a cross section as shown. TheLED 32 has a central radiation surface 39 a at the center of its uppersurface 39 and, subsequently to the central radiation surface 39 a, anupper reflection surface 39 b with an umbrella-like shape to be formedby rotating, around the Z-axis, part of a parabola with a symmetry axison the X-axis in the range of 60 degrees or more to the Z-axis from theorigin (i.e., it is not a paraboloid of revolution). A side radiationsurface 40 of LED 32 composes part of spherical surface centered at thelight emitting element 36. The LED 32 thus composed is fixed at thecenter of the circular LED light 31.

The radiation principle of the LED light 31 thus composed will beexplained with reference to FIG. 11 and FIG. 12. When a voltage isapplied to the lead plates 35 a, 35 b of LED 32, the light emittingelement 36 emits light. Of light emitted from the light emitting element36, a light component heading to the Z-axis direction, i.e., upward isradiated out of the transparent resin 38 from the central radiationsurface 39 a, and is externally radiated passing through a transparentfront plate (not shown) disposed covering the LED light 31. Further, oflight emitted from the light emitting element 36, a light component inthe range of 60 degrees or more to the Z-axis reaches the upper surface39 as the first reflection mirror, being all subjected to totalreflection due to a large incident angle to the upper surface 39, thenheading to the side radiation surface 40. Since the upper reflectionsurface 39 b has a shape to be formed by rotating part of a parabolawith a symmetry axis on the X-axis and with a focal point at the lightemitting element 36 around the Z-axis, all of light reflected by theupper surface 39 proceeds parallel to the X-Y plane, directly passingnearly in parallel through the side radiation surface 40 which composespart of spherical surface centered at the light emitting element 36,then being externally radiated forming nearly a plane in directions of360 degrees around the Z-axis. Further, light directly heading to theside radiation surface 40 from the light emitting element 36 goesstraight without refraction since the side radiation surface 40 composespart of spherical surface centered at the light emitting element 36,then being radiated externally.

The stepwise reflection mirror 33 as the second reflection mirror liesahead. It has the reflection surface 33 a with an inclination of about45 degrees, and each light being reflected by the reflection surface 33a proceeds upward nearly vertically since light being reflected by theupper surface 39 nearly in parallel with the X-Y plane and light beingdirectly radiated from the side radiation surface 40 proceeds inparallel with the X-Y plane. It is externally radiated passing through atransparent plate (not shown) at least in the range of 20 degrees fromthe Z-axis. Although even light represented as “parallel” in the aboveexplanation is not perfectly parallel since the light emitting element36 has a size, any light thereof is radiated nearly in parallel and issurely included at least in the range of 20 degrees from the Z-axis.

As described, the LED light 31 in embodiment 1B can be low-profile andcan radiate light in a large area by using one light emitting elementwhile taking advantage, low-profile, of LED, and it can offer a highexternal radiation efficiency.

An application of the LED light 31 in embodiment 1B is shown in FIG. 13.The circular LED light 31 is cut to form a square or a shape includingpart of square, and six segments 41 a, 41 b, 41 c, 41 d, 41 e and 41 fthus cut can be combined, as shown, to form an integrated LED light 41with multiple light emitting elements to cover a predetermined area.

[Modification 1]

As shown in FIG. 14, the first modification of the LED light 31 inembodiment 1B may be composed such that a pair of lead plates 42 a, 42 bare caved only around the light emitting element 36 to provide a thirdreflection mirror. Thereby, although in the basic form in FIG. 12 lightis radiated directly upward only from directly over the light emittingelement 36, light can be also radiated upward from around the lightemitting element 36 in LED. Thus, it further appears the entire portionemits light and, thereby, the appearance can be enhanced.

[Modification 2]

As shown in FIG. 15, the second modification of the LED light 31 inembodiment 1B may be composed such that a pair of lead plates 43 a, 43 bare provided with a pattern by half etching or stamping pattern toreflect light to be radiated obliquely downward from the light emittingelement 36 to radiate it upward. By forming multiple concentricreflection mirrors, like modification 1, it further appears the entireportion emits light and, thereby, the appearance can be enhanced. Inthis case, an adhesion area between transparent resin 38 and lead plates43 a, 43 b increases and, thereby, release failure can be reducedbecause of having an adhesion form other than a plane. Especially, itwill be effective for a large current type with much heat generation.

[Modification 3]

As shown in FIG. 16, the third modification of the LED light 31 inembodiment 1B may be composed such that the sealing member oftransparent epoxy resin 38 in LED has another side shape. In the basicexample the side surface 40 composes part of spherical surface centeredat the light emitting element 36 and light emitted from the lightemitting element 36 is thus entered nearly perpendicularly into the sidesurface 40 then directly going straight. However, in modification 3,since a side 44 composes part of ellipsoid surface that has one focalpoint at the light emitting element 36, light emitted from the lightemitting element 36 is refracted slightly downward to the straightdirection in the side 44. Therefore, even when the stepwise reflectionmirror 33 around LED is placed further low, the LED light can offer highexternal radiation efficiency. Thus, the LED light can be furtherlow-profile.

[Modification 4]

As shown in FIG. 17, the fourth modification of the LED light 31 inembodiment 1B may be composed such that a metal reflection film 45 isformed on the upper surface 39 by plating or evaporation to conductreflection in the side direction at the upper surface 39 as the firstreflection mirror without using total reflection at the boundary oftransparent resin 38 and air. In this case, if a plane is formeddirectly over the light emitting element 36, light to be radiateddirectly upward cannot be externally radiated. Therefore, it is neededthat, also at the center of upper surface 39, the upper surface 39 has ashape to be formed by rotating, around the Z-axis, part of a parabolawith a focal point located at the light emitting element 36.

[Modification 5]

The fifth modification (51) of the LED light 31 in embodiment 1B may becomposed such that emission points are dotted whereas in the basicexample the entire portion emits light nearly evenly. Namely, as shownin FIGS. 18( a), a circular reflection mirror 53 as the secondreflection mirror is divided into fan-shaped sections and a distancefrom LED 52 to reflection surface 53 a is differentiated as shown inFIGS. 18( b), (c) and (d). Therefore, viewing from the top, positions toreflect light are scattered in the circle and, thereby, an effect thatit appears glittering can be obtained. Further, since LED 52 is providedwith a small central radiation surface 4 a, its appearance becomesbetter. Namely, the brightness of light to be externally radiated fromthe central radiation surface 4 a and the reflection surfaces 53 a canbe equalized and luminescent spots can be arranged in good balance. Thebrightness can be equalized by reducing the amount of light to beexternally radiated from the central radiation surface 4 a to a smallratio such as less than 1/10 to that to be externally radiated reflectedby the circular reflection mirror 53 after being radiated to theperiphery of LED 52, i.e., by controlling most of light to be radiatedto the periphery of LED 52. Further, in detail, as the circularreflection mirror 53 becomes bigger, the ratio of light to be externallyradiated from the central radiation surface 4 a may be reduced. Althoughthe glittering effect can be obtained when the reflection surface 53 ais nearly planar or convex, the ratio of light to be externally radiatedfrom the central radiation surface 4 a may be reduced according as thecurvature of convex surface becomes larger. In modification 5, sincelight from LED 52 is to be all reflected by the single-stage reflectionsurface 53 a at each fan-shaped section, it is desired that, as shown inFIGS. 18( b), (c) and (d), the height of reflection surface 53 a is thesame as the total height h of circular stepwise reflection mirror 33 inthe basic example as shown in FIG. 11( b). Although the brightness isequalized in the above example, the brightness may be accented such thatit becomes high toward the periphery or the other way around.

[Modification 6]

As shown in FIG. 19, the sixth modification (54) of the LED light 31 inembodiment 1B may be composed such that a reflection mirror 56 as thesecond reflection mirror is divided into fan-shaped sections withdifferent lengths to allow the shape of reflection mirror 56 to be closeto a square as one of polygons. Namely, as shown in FIGS. 19( b) and(c), provided that, in the shortest fan-shaped section, L is a lengthfrom reflection surface 56 a to the next reflection surface 56 a, thelongest fan-shaped section separated 45 degrees from that section ismade to have a length of √{square root over (2)}L from reflectionsurface 56 a to the next reflection surface 56 a. Thereby, as shown inFIG. 13, when combining multiple square LED lights 41 a, . . . , it isnot necessary to cut a circular LED light into a square. Therefore,reduction in external radiation efficiency can be prevented and acombined light can be offered with higher brightness. Further, when anearly square LED is used as a light source instead of a nearlycylindrical LED 55, there is an advantage that a distance between theside of LED and reflection mirror 56 becomes nearly equal over thecircumference.

Embodiment 1C

Embodiment 1C of the invention will be explained below with reference toFIG. 20.

As shown in FIG. 20, LED 61 in embodiment 1C of the invention iscomposed such that, of a pair of lead plates 63 a, 63 b, the lead plate63 a has a light emitting element 64 mounted on its tip, and an upperelectrode of light emitting element 64 is electrically connected througha wire 65 to the tip of lead plate 63 b. The tip portion of lead plates63 a, 63 b, light emitting element 64 and wire 65 as electric system aresealed with transparent epoxy resin 66 as a light-transmitting material.The transparent epoxy resin 66 is shaped such that an upper portion ofsemisphere centered at the light emitting element 64 is cut off like acircular cone. In this case, although light radiated from the lightemitting element 64 is subjected to total reflection at upper surface 62as the first reflection mirror, its reflected light corresponds toradiation light from a mirroring point of light emitting element 64 tothe upper surface and, therefore, it is not converged and radiated fromits side 67 while having a divergence angle. Thus, it is needed that acircular stepwise reflection mirror as the second reflection mirror forreflecting light upward has a height in the Z-axis direction greaterthan that for LED 32 in embodiment 1B.

In the case that a relatively wide light distribution is allowed in LEDlight or a very low-profile shape is not required in LED light, such thesimple circular cone reflection surface 62 can be used.

Embodiment 1D

Embodiment 1D of the invention will be explained below with reference toFIG. 21.

As shown in FIG. 21, LED 70 in embodiment 1D of the invention iscomposed such that, of a pair of lead plates 63 a, 63 b, the lead plate63 a has a light emitting element 64 mounted on its tip, and an upperelectrode of light emitting element 64 is electrically connected througha wire 65 to the tip of lead plate 63 b. The tip portion of lead plates63 a, 63 b, light emitting element 64 and wire 65 as electric system aresealed with transparent epoxy resin 66. The transparent epoxy resin 66is shaped like a regular cylinder and therefore the upper surface oftransparent epoxy resin 66 does not serve as the first reflectionmirror. Instead, an optical member 68 like an umbrella molded withtransparent acrylic resin is attached through a light-transmittingmaterial 67 onto the upper surface of transparent epoxy resin 66. Theoptical member 68 has an upper surface 69 with a shape to be formed byrotating, around the Z-axis, part of a parabola with a focal point atthe light emitting element 64 and with a symmetry axis on the X-axis.

A lower surface 71 of the optical member 68 is formed circular andstepwise with steps of about 45 degrees to replace the circular stepwisereflection mirror in embodiment 2 (1B) as the second reflection mirror.The lower surface 71 is provided with aluminum evaporation 72 on whichan overcoat (not shown) is formed thereon to protect the aluminumevaporation film. In the present embodiment 4 (1D), a degree of freedomin overcoat after forming the evaporation mirror surface can beincreased. Namely, the overcoat may be colored and its thickness is notlimited.

The LED light 70 thus composed is operated such that a predeterminedvoltage is applied to the pair of lead plates 63 a, 63 b, the lightemitting element 64 emits light, light heading upward directly goesstraight because of not being blocked, being externally radiated passingthrough a transparent front plate (not shown). On the other hand, lightradiated between obliquely upward and sideward is entered into theoptical member 68 while passing through the light-transmitting material67. Light being irradiated to the upper surface 69 as the firstreflection mirror is subjected to total reflection and is all reflectedsideward nearly in parallel with the X-Y plane since the upper surface69 has a shape to be formed by rotating, around the Z-axis, part of aparabola with a focal point at the light emitting element 64. Then, itis reflected upward nearly in parallel with the Z-axis by the lowersurface (circular stepwise reflection mirror) 71 as the secondreflection mirror, being externally radiated passing through the uppersurface 69 and the front plate. In like manner, light being directlyirradiated to the lower surface (circular stepwise reflection mirror) 71is radiated upward.

As described, the LED light in embodiment 1D can be low-profile and canradiate light in a large area by using one light emitting element whiletaking advantage, low-profile, of LED, even when using a regularcylindrical LED and it can offer high external radiation efficiency.

Embodiment 1E

Embodiment 1E of the invention will be explained below with reference toFIG. 22.

As shown in FIG. 22, an LED light 80 in embodiment 1E is formed on analuminum base 81 as a metal board. A circuit pattern 83 is formed on thealuminum base 81 to sandwich an insulation layer 82 and a light emittingelement 84 is mounted thereon while having electrical connection througha wire 85. An optical member 87 like an umbrella concaved by asemisphere 91 molded with transparent acrylic resin is mounted on thecircuit pattern 83, light emitting element 84 and wire 85 as electricsystem. In this case, transparent silicon resin as light-transmittingmaterial is filled in the semisphere 91 and thereby the circuit pattern83, light emitting element 84 and wire 85 are sealed. In the state ofbeing thus fixed, the optical member 87 has an upper surface 88 with ashape to be formed by rotating, around the Z-axis, part of a parabolawith a focal point at the light emitting element 84.

A lower surface 89 of the optical member 88 is formed circular andstepwise with steps of about 45 degrees to serve as the secondreflection mirror. The lower surface 89 is provided with aluminumevaporation 90 on which an overcoat (not shown) is formed thereon toprotect the aluminum evaporation film. Also in the present embodiment1E, a degree of freedom in overcoat after forming the evaporation mirrorsurface can be increased. Namely, the overcoat may be colored and itsthickness is not limited.

The LED light 80 thus composed is operated such that the light emittingelement 84 emits light, light heading upward directly goes straightbecause of not being blocked, being externally radiated passing througha transparent front plate (not shown). On the other hand, light radiatedbetween obliquely upward and sideward is entered into the optical member87 while passing through the light-transmitting material 86. Light beingirradiated to the upper surface 88 as the first reflection mirror issubjected to total reflection and is all reflected sideward nearly inparallel with the X-Y plane since the upper surface 88 has a shape to beformed by rotating, around the Z-axis, part of a parabola with a focalpoint at the light emitting element 84. Then, it is reflected upwardnearly in parallel with the Z-axis by the circular stepwise reflectionmirror 89 as the second reflection mirror, being externally radiatedpassing through the upper surface 88 and the front plate. In likemanner, light being directly irradiated to the circular stepwisereflection mirror 89 is radiated upward.

The LED light 80 in the present embodiment 1E is mounted on the aluminumbase 81 with a good thermal conductivity and thereby the heat radiationproperty can be significantly enhanced. Thus, even when large current isflown through the light emitting element 84, heat saturation does notoccur. Therefore, a large optical output can be obtained.

As described, the LED light in embodiment 1E can be low-profile, withhigh brightness and can radiate light in a large area as well as havingan enhanced heat radiation property and offering a large optical outputwithout being affected by heat saturation.

Embodiment 1F

Embodiment 1F of the invention will be explained below with reference toFIG. 23.

As shown in FIG. 23, an LED light 100 in embodiment 1F is also formed onan aluminum base 95 as a metal board. A circuit pattern 97 is formed onthe aluminum base 95 to sandwich an insulation layer 96 and a lightemitting element 98 is mounted thereon while having electricalconnection through a wire 99. The circuit pattern 97, light emittingelement 98 and wire 99 as electric system are sealed with transparentepoxy resin 102 as a light-transmitting material. An optical member 101molded with circular transparent acrylic resin is mounted thereon. Inthe state of being thus fixed, the optical member 101 has an uppersurface 103 with a shape to be formed by rotating, around the Z-axis,part of a parabola with a focal point at the light emitting element 98,and it serves as the first reflection mirror.

A lower surface 104 of the optical member 101 is formed circular andstepwise with steps of about 45 degrees to serve as the secondreflection mirror. In the LED light 100 of the present embodiment 1F,the lower surface 104 is not provided with metal evaporation. Namely,light from the light emitting element 98 to be reflected sideward by theupper surface 103 of optical member 101 as the first reflection mirroris reflected upward due to total reflection at the lower surface 104 ofoptical member 101 as the second reflection mirror. Thus, even withoutmetal evaporation formed on the lower surface 104 of optical member 101,most of light can be reflected upward only by the total reflection atthe lower surface 104. In order to reflect light that passes through thelower surface 104 without being subjected to the total reflection, asupplemental reflection member 105 is mounted on the circuit board 97while providing an air layer under the lower surface of optical member101. The supplemental reflection member 105 has an upper surface with areflection surface formed thereon by plating and serves to upwardlyreflect light passing through the lower surface 104.

In the LED light 100 of the present embodiment 1F, it is not necessaryto provide the metal evaporation with the lower surface 104 of opticalmember 104 that serves both as the first reflection mirror and as thesecond reflection mirror, and the supplemental reflection member 105with coating formed by simple plating only has to be provided to allowalmost all of light emitted from the light emitting element 98 to beupwardly radiated. Thus, the high external radiation efficiency can beobtained.

The LED light 100 in the present embodiment 1F is also mounted on thealuminum base 95 with a good thermal conductivity and thereby the heatradiation property can be significantly enhanced. Thus, even when largecurrent is flown through the light emitting element 98, heat saturationdoes not occur. Therefore, a large optical output can be obtained.

As described, the LED light in embodiment 1F be low-profile, with highbrightness and can have the high external radiation efficiency by usingthe simple process as well as having an enhanced heat radiation propertyand offering a large optical output without being affected by heatsaturation.

Embodiment 1G

Embodiment 1G of the invention will be explained below with reference toFIG. 24.

As shown in FIG. 24, an LED light 110 in embodiment 1G is composed of:an optical member 111 that is molded with transparent acrylic resin andhas a lower surface 113 which is a stepwise reflection surface to serveas the second reflection mirror and a cylindrical space 114 formed atthe center; and LED 32, like the LED light 31 in embodiment 1B, that isfixed in the space 114 at the center. Namely, the LED 32 is composedsuch that a light emitting element 115 etc. are sealed with transparentepoxy resin and has a paraboloid 116 at the upper surface as the firstreflection mirror. Light to be radiated from the light emitting element115 and sideward reflected by the upper surface 116 is upwardlyreflected by the lower surface 113 of optical member 111 and thenexternally radiated passing through a front plate (not shown).

In the LED light 31 of embodiment 2 (1B), light to be directly (withoutbeing reflected by the upper surface 116) radiated from upper portion ofthe side surface 117 of LED 32 is not utilized without being upwardlyreflected while proceeding along a path indicated by a two-dotted line.However, in the LED light 110 of the present embodiment 1G, it can beutilized such that it is, as indicated by a dotted line, reflected bythe horizontal upper surface 112 of optical member 111 and thenreflected upwardly by the lower surface 113. Thus, the LED light can below-profile and with further enhanced external radiation efficiency.Further, light to be entered into the space 114 is refracted in adirection to give a large angle to the Z-axis and thereby the brightnessat the periphery in viewing from the top in FIG. 24( a) can be enhanced.

In the above embodiments, transparent acrylic resin is used for theoptical member that serves as the second reflection mirror or both asthe first reflection mirror and as the second reflection mirror.However, the other material such as another transparent synthetic resinmay be used for that.

Although the above embodiments explain that the central radiationsurface is provided to take out light radiated from the center of LED,light radiated from the center of LED may be taken out without thecentral radiation surface by using a large size light emitting elementor placing the upper surface optical system just nearby to make anincident angle from the light emitting element to the upper surfaceoptical system to be within a critical angle.

Alternatively, when using a light emitting element with a narrow lightdistribution, a sufficient lateral radiation can be obtained withoutalways placing the upper surface optical system nearby.

The composition, shape, number, material, dimensions, connection formetc. of the other part in the LED light are not limited to thosedescribed in the above embodiments.

Embodiment 2A

FIG. 25( a) is a plain view showing an LED light 201 in embodiment 2A ofthe invention, (b) is a cross sectional view cut along the line A-A in(a), and (c) is an enlarged cross sectional view showing part P of (b).The LED light 201 is composed of: an LED 202 that has a light emittingelement 206 with a predetermined light distribution characteristic atthe center of a disk-shaped body; and a reflection mirror 203 that has aconcentric and stepwise reflection surface 203 a around the LED 202.

The reflection mirror 203 is molded of transparent acrylic resin and,after molding, the reflection surface 203 a is formed by providingaluminum evaporation thereon to mirror-finish it. The reflection surface203 a is, as shown in FIG. 25( a), inclined about 45 degrees to the X-Yplane such that light to be entered from the X(Y) direction is reflectedto the Z-axis direction.

FIG. 26( a) is a cross sectional view showing the LED 202, (b) is aplain view thereof, and (c) is a side view thereof. The LED 202 iscomposed of: lead frames 205 a, 205 b; a light emitting element 206; abonding wire 207 to provide electrical connection between the lead frame205 b and light emitting element 206; transparent epoxy resin 208 thatis with an optical surface while integrally sealing the lead frames 205a, 205 b and light emitting element 206; a reflection mirror 209 thathas a central radiation surface 209 a and a reflection surface 209 b;and a radiation surface 210 that composes part of a sphere centered atthe light emitting element 206 to radiate light in the X-Y direction.

The lead frames 205 a, 205 b are of copper alloy and disposed having agap for insulation on the X-Y plane, and the lead frame 205 a with alarge area has the light emitting element 206 mounted on an originposition thereof.

The light emitting element 206 is formed cubic, face-up bonded to thelead frame 205 a and provided with an emission surface on its top. It isof large current type (high output type) in order to keep the emissionintensity of LED 202 at a predetermined value while reducing the numberof elements used as much as possible. The light emitting element 206 maybe flip-chip mounted on the lead frame 205 a.

The transparent epoxy resin 208 is of epoxy resin with a refractiveindex of 1.55 and has the central radiation surface 209 a at the center(directly over the light emitting element 206) of upper surface thereof.The reflection mirror 209 is constructed such that the reflectionsurface 209 b is formed continuously with the central radiation surface209 a. A proximity optical system is formed by disposing the lightemitting element 206 close to the reflection mirror 209 and thenintegrally molding with resin.

The reflection mirror 209 is composed of the central radiation surface209 a to radiate directly upwardly light radiated from the lightemitting element 206, and the reflection surface 209 b that has acircular reflection shape to be formed by rotating, around the centeraxis Z, part of a parabola with a focal point at the center of emissionsurface of light emitting element 206 as the coordinate origin in FIG.26 and with a symmetry axis on the X-axis. Alternatively, according touse, the reflection mirror 209 may be not provided with the centralradiation surface 209 a.

The reflection mirror 209 is the first reflection mirror to reflectlight radiated from the light emitting element 206. As shown in FIG. 26(c), the radius R of reflection surface 209 b is given such that almostall of light being radiated with a large sold angle to the lightemitting element 206 can be effectively radiated sideward. In thisexample, where a height from the emission surface of light emittingelement 206 to the edge of reflection mirror 209 in the Z-axisdirection, H=2.0 mm and R=3.5 mm are given, the relationship between theedge height H of reflection mirror 209 and radius R is H<R. Further, inorder to form a proximity optical system to provide a relatively largesolid angle, the distance (thickness of transparent epoxy resin 208) hbetween the light emitting element 206 and the central radiation surface209 a is set to be 0.5 mm.

FIG. 27 shows the composition of light emitting element 206. In theorder of the bottom layer to the top layer, n-GaAs substrate 221,n-AlInGaP cladding layer 222, a layer 223 including a light emittinglayer, p-AlInGaP cladding layer 224 and p-GaP window layer 225 areformed. On the p-GaP window layer 225, Al bonding pad (positiveelectrode) 227 is formed through AuZn contact layer 226 for the ohmiccontact with the window layer 225. Further, under the n-GaAs substrate221, Au alloy electrodes (negative electrodes) 228 are formed. Then-GaAs 221 substrate is not transparent to a wavelength of light emittedfrom the light emitting layer. The n-AlInGaP cladding layer 222 andp-AlInGaP cladding layer 224 are transparent thereto.

FIG. 28 is an illustration showing a light distribution characteristicof the light emitting element 206. A radiation intensity to be radiatedfrom the top surface 206 a and side surfaces 206 b (four side surfaces)of light emitting element 206 is the sum of radiation intensity to beradiated from the top surface 206 a and radiation intensity to beradiated from the four side surfaces 206 b. The light distributioncharacteristic I(θ) is represented by the next formula (1):I(θ)=k·cos θ+(1−k)·sin θ  (1),where k·cos θ indicates radiation intensity to be radiated from the topsurface 206 a and (1−k)·sin θ indicates radiation intensity to beradiated from the side surface 206 b. θ is an angle to the Z-axis inlight emitting element 206. As k is changed, the distribution of lightto be radiated from the top surface 206 a and light to be radiated fromthe side surface 206 b is changed.

FIG. 29 shows a change in radiation intensity (in the Z-axis direction)when θ is changed in light emitting element 206 with different lightdistribution characteristics based on the above formula (1). FIG. 29( a)shows a definition of angle to the light emitting element 206. FIG. 29(b) shows the state (top 100%) of light of 100% being radiated from thetop surface 206 a at k=1. FIG. 29( c) shows the state (top 80%) of lightof 80% being radiated from the top surface 206 a at k=0.8 and light of20% being radiated from the side surface 206 b. FIG. 29( d) shows thestate (top 60%) of light of 60% being radiated from the top surface 206a at k=0.6 and light of 40% being radiated from the side surface 206 b.

The light emitting element 206 has a characteristic at about k=0.8 thatthe ratio of light radiated from the top surface to light emitted fromthe layer 223 including light emitting layer becomes big since n-GaAssubstrate 221 is a black absorbing material to emission color. Namely,light of 80% is radiated from the top surface 206 a and light of 5% isradiated from each side surface 206 b. In order to have a desired lightdistribution characteristic, the thickness of epitaxial layer or theshape of light emitting element 206 is controlled.

The light emitting element 206 with a light distribution characteristicas shown in FIG. 29( b) is characterized such that light is radiatedfrom the top surface 206 a, the radiation intensity lowers as θincreases and it becomes nearly zero at θ=90 degrees. The light emittingelement 206 with a light distribution characteristic as shown in FIG.29( c) is characterized such that light is also radiated from the sidesurface 206 b, radiation intensity at θ=0 is smaller than that of thelight emitting element in FIG. 29( b) and it however does not becomezero even at 90 degrees and therefore light is radiated in the X-Ydirection. The light emitting element 206 with a light distributioncharacteristic as shown in FIG. 29( d) is characterized such that theamount of light radiated from the side surface 206 b is greater thanthat in FIG. 29( c) and, therefore, radiation intensity at θ=0 issmaller and, however, a reduction in radiation intensity along with achange of θ is smaller than that in FIG. 29( b) and (c), and it does notbecome zero even at 90 degrees and therefore light is radiated in theX-Y direction.

The light distribution characteristic of LED 202 depends on the lightdistribution characteristic of light emitting element 206, a positionprecision of optical surface in the light emitting element 206, centralradiation surface 209 a, reflection surface 209 b and radiation surface210, a mounting position precision of the light emitting element 206 tothe lead frame 205 a, and a setting position precision of the lead frame205 a and above optical surface to a die in molding integrally withresin. In order not to cause an unevenness in light distribution in θdirection as shown in FIG. 26( b), evenness in light to be radiated inthe circumference direction (360 degrees) of radiation surface 210centered at the Z-axis is required. If a displacement exists between thelight emitting element 206 and optical surface, unevenness In LightDistribution in θ direction is generated according to the amount ofdisplacement. Especially, the proximity optical system of LED 202 in theinvention has such a compositional characteristic that it is likely togenerate unevenness in light distribution due to a slight displacement.

FIG. 30 shows a change in light amount of light radiated directly upwardfrom the LED 202 and light irradiated to the reflection surface 203 a,caused by a change in light distribution characteristic generated when,in the LED 202, the center axis of light emitting element 206 isdisplaced in the X-axis direction to the optical surface. In the case oflight emitting element 206 with GaAs substrate, the effective radiationefficiency ratio lowers when a displacement is generated in the X-axisdirection in manufacture. In FIG. 30, it significantly lowers,particularly, more than 0.3 mm.

FIGS. 31( a) and (b) show observation conditions of light amountradiated from LED 202, where the entire circumference of LED 202 isdivided into φij to represent 32 regions. As shown in FIG. 31( a), itscircumference of 360 degrees centered at the Z-axis is divided intoeight sections (j=1 to 8). FIG. 31( b) shows an angle range of 0 to 20degrees (i=1) to the Z-axis, an angle range of 20 to 60 degrees (i=2),an angle range of 60 to 100 degrees (i=3), and an angle range of 100 to180 degrees (i=4). The amount of light radiated from LED 202 to thesesregions will be explained below. Herein, it is assumed that a region inangle range of 0 to 20 degrees to the Z-axis corresponds to light to bedirectly externally radiated near the Z-axis from LED 202 and a regionin angle range of 60 to 100 degrees to the Z-axis corresponds to lightto be radiated from LED 202 to the reflection mirror 203 then reflectedin a direction near the Z-axis by the reflection mirror 203 to beradiated externally.

FIG. 32 shows a deviation in total light amount of LED 202 in using thelight emitting element 206 with a top light distribution characteristicof 100% under the observation conditions as shown in FIG. 31. Thedeviation of total light amount is calculated under conditions that sixdisplacements of 0.0 to 0.5 mm in the X-axis direction are generated,and the deviation of total light amount in each direction is shownconnected with lines. As the amount of displacement increases, thedeviation of total light amount increases. FIG. 32( b) shows a deviationin total light amount of LED 202 in using the light emitting element 206with a top light distribution characteristic of 80%. Since the lightemitting element 206 has a structure to radiate light from the sidesurface 206 b, the deviation of total light amount is improved.

As described above, as the amount of light radiated laterally from thelight emitting element 206 increases, the deviation of total lightamount in effective radiation range due to a displacement between thelight emitting element 206 and optical surface is reduced. Therefore,when using a light emitting element 206 with a light distributioncharacteristic of less than k=0.8, the deviation of total light amountin effective radiation range is almost removed and no visual influenceis generated. This is because, even when the position of a lightemitting element 206 mounted on the lead frame 205 a is deviated within0.1 mm in the X-axis (Y-axis) direction from the Z-axis, its influencecan be compensated by the light distribution characteristic of lightemitting element 206.

The LED 202 may be fabricated by, e.g., transfer molding as explainedreferring to FIG. 9.

The operation of LED light 201 will be explained below.

When an operator turns on a power switch (not shown) of LED light 201,power source section (not shown) applies a voltage to the lead frames205 a, 205 b. The light emitting element 206 emits light based on theapplying of voltage. Light emitted directly upward along the Z-axis fromthe light emitting element 206 is externally radiated out of thetransparent epoxy resin 208 from the central radiation surface 209 a. 50to 60% of light to be emitted from the light emitting element 206 isirradiated to the reflection surface 209 b with a solid angle of about2.7 strad to the light emitting element 206. Light to be emitted in adirection nearly horizontal from the light emitting element 206 isdirectly irradiated to the radiation surface 210, directly radiatedexternally in a direction nearly parallel to the X-Y plane from theradiation surface 210.

Light to be radiated nearly parallel to the X-Y plane from the LED 202is reflected nearly in the Z-axis direction by the reflection surface203 a of reflection mirror 203, then radiated externally.

As described above, the LED light 201 in embodiment 2A described aboveis composed such that the light emitting element 206 of LED 202composing a proximity optical system has a light distributioncharacteristic of less than k=0.8 in I(θ)=k·cos θ+(1−k)·sin θ and thelight emitting element 206 and optical surface are integrally formed bytransfer molding. Light in the X-axis direction to be radiated from theLED 202 and irradiated to the reflection mirror 203 has little deviationof total light amount in effective radiation range and can be radiatedalmost evenly in the Z-axis direction by the reflection mirror 203.Thereby, a low-profile lamp with a good appearance can be offered whilehaving a large area of reflection mirror and no difference in surfacebrightness. When it is applied to a tail lamp or a brake lamp ofautomobile, visibility of light can be enhanced not only in the backdirection of automobile but also in the lateral direction thereof.

Although the above LED light 201 is exemplified such that the LED 202uses the light emitting element 206 with a light distributioncharacteristic of k=0.8, if it uses a light emitting element 206 with alight distribution characteristic of less than k=0.8, then the deviationof total light amount in effective radiation range due to a displacementbetween the light emitting element 206 and optical surface can bereduced to a level causing no problem practically.

In the manufacture by transfer molding, transparent epoxy resin 208 isinjected into a die while sandwiching the lead frames 205 a, 205 b bythe die. Therefore, the positioning between the light emitting element206 and optical surface can be performed at a high precision of ±0.1 mm.Thereby, even when using the proximity optical system composed of alight emitting element 206 with k=0.8, the LED light 201 with astabilized quality can be offered while preventing a dispersion in lightdistribution characteristic due to an individual difference of the LED202.

Although in the above explanation transparent epoxy resin 208 is used asthe transparent material to seal the light emitting element 206, anothertransparent material having about the same transparency and the otheroptical characteristics may be used. Further, although transparentacrylic resin is used for the reflection mirror 203, the other materialsuch as another transparent synthetic resin may be used for that.

The composition, shape, number, material, dimensions, connection formetc. of the other part in the LED light are not limited to thosedescribed in the above embodiments.

Although the reflection surface 209 b is provided to offer the totalreflection of resin without being mirror fished, it may be alternativelymirror finished by metal evaporation etc.

Embodiment 2B

FIG. 33( a) is a plain view showing an LED 202 a in embodiment 2B of theinvention in viewing from the Z-axis direction, and (b) is a crosssectional view showing the vicinity of a light emitting element 206 in(a). The LED 202 a is composed of: the light emitting element 206 thatis of GaP substrate AlInGaP using a n-GaP substrate with a transparencyand has a light distribution characteristic of top 60% (k=0.6); and leadframes 205 b, 205 c that are of copper alloy and folded at itsresin-sealed region. The light emitting element 206 is mounted on thetip of lead frame 205 c. Like parts are indicated by the same numeralsused in embodiment 2A and the explanations thereof are omitted here.

FIG. 34 shows a deviation in total light amount of LED 202 a using alight emitting element 206 with a light distribution characteristic ofk=0.6. As shown, even when X=0.4, the deviation in light distributioncharacteristic is kept within ±20% since the amount of light to beradiated from the side surface 206 b of light emitting element 206 isincreased, as compared to the light emitting element 206 with a lightdistribution characteristic of k=0.8. Thus, the deviation in total lightamount is improved. The light emitting element 206 with k=0.6 may beformed using a substrate material that offers a light transparency toemission color of GaP etc. in order to increase the radiation amountfrom the side surface 206 b based on a reflection in of the lightemitting element 206.

LED 202 a may be fabricated by, e.g., casting mold as explainedreferring to FIG. 10.

Since the LED 202 a in embodiment 2B has the light emitting element 206using the n-GaP substrate with a transparency and it has a lightdistribution characteristic of k=0.6, it can have a wider lightdistribution characteristic than LED 202 with the light emitting element206 using the n-GaAs substrate. Thereby, even if a small displacement isgenerated between the light emitting element 206 and optical surface,the deviation of total light amount in effective radiation range can bereduced to a level causing no problem practically.

In the casting mold, since the tip (free and) of lead frames 205 b, 205c is not restrained by the casting, precision in positioning between thelight emitting element 206 and optical surface lowers to ±0.2 mm ascompared to that in the transfer molding. Especially, when the lightemitting element 206 is mounted on the tip thick portion of planar leadframe, it is difficult to obtain a high precision in positioning.However, since the tolerance of precision in positioning is increased,the productivity can be enhanced and therefore it has an excellent massproduction property. By curing the transparent epoxy resin 208 for longhours, unevenness in thermal stress is reduced and the lead frames 205b, 205 c are not likely to be released from the transparent epoxy resin208. Meanwhile, by choosing the fabrication process management and thelight distribution characteristic of light emitting element 206, thelight distribution characteristic can be stabilized.

Embodiment 2C

FIG. 35( a) is a plain view showing an LED 202 b in embodiment 2C of theinvention in viewing from the Z-axis direction, and (b) is a crosssectional view showing the vicinity of a light emitting element 206 in(a). The LED 202 b is composed of: the light emitting element 206 thatis of GaP substrate AlInGaP using a n-GaP substrate with a transparencyand has a light distribution characteristic of top 40% (k=0.4); and leadframes 205 b, 205 d that are of copper alloy. Like parts are indicatedby the same numerals used in embodiments 2A, 2B and the explanationsthereof are omitted here.

The light emitting element 206 with k=0.4 has dimensions (e.g., 0.3 mmsquare) smaller than the light emitting element 206 with k=0.6, andthereby the radiation amount from the side surface 206 b is furtherincreased since the absorption loss in light emitting element isreduced.

The light emitting element 206 is mounted on the tip of lead frame 205 cpunched out by pressing.

Since the LED 202 b in embodiment 2C has the light emitting element 206mounted on the tip of lead frame 205 c, it can have a reduced contactarea between the lead frames 205 b, 205 d and transparent epoxy resin208, thereby preventing the releasing, as well as having an excellentmass production property while reducing the deviation in total lightamount in effective radiation range. Further, the process of folding thelead frames 205 b, 205 d is not needed and therefore the productivitycan be enhanced.

Further, since the LED 202 b in embodiment 2C has the light emittingelement 206 using the n-GaP substrate with a transparency, it can have awider light distribution characteristic than LED 202 with the lightemitting element 206 using the n-GaAs substrate, like embodiment 2B.Thereby, even if a small displacement is generated between the lightemitting element 206 and optical surface, the deviation of total lightamount in effective radiation range can be reduced to a level causing noproblem practically.

Embodiment 2D

FIG. 36 shows an LED 202 c in embodiment 2D of the invention. The LED202C is composed of: a light emitting element 206 of Al₂O₃ substrateGaN; lead frames 205 b, 205 d that are of copper alloy and folded at itsresin-sealed region; and transparent epoxy resin 208 with an opticalsurface. The light emitting element 206 is mounted on the tip of leadframe 205 d. The light emitting element 206 is sealed with sealing resin208 s including phosphor. In FIG. 36, the transparent epoxy resin 208 isshown as transparent member. Like parts are indicated by the samenumerals used in embodiment 2A, 2B, 2C and the explanations thereof areomitted here.

Since the LED 202 c in embodiment 2D has the light emitting element 206that is mounted on the tip of lead frame 205 d and sealed with sealingresin 208 s in the shape of a semisphere, even when the light emittingelement 206 does not have a wide light distribution characteristic,excitation light to be radiated from phosphor can be diffused. Thereby,its light distribution characteristic can be made to be suitable for theproximity optical system of the invention.

The phosphor available is Ce:YAG (yttrium aluminum garnet) etc. In orderto enhance the light distribution characteristic, a light diffusionmaterial for diffusing light may be mixed into the sealing resin 208 sinstead of the phosphor. Thereby, the same effect can be obtained. Thelight diffusion material may be, e.g., titanium oxide, alumina, SiO2.

Although in the above embodiments 2A to 2D the light emitting element206 uses a GaAs system substrate, it may use a GaP substrate AlInGaPsystem or GaN system according to the light distribution characteristic.Further, it may selectively use a substrate with a transparency ornon-transparency to emission wavelength. If applicable to the LED light201, the light emitting element 206 is not limited to specificcomposition.

Although the light emitting diode is formed by molding the reflectionsurface and side reflection surface while sealing the light emittingelement, it may be formed by sealing the light emitting element with alight-transmitting material while mounting a mold with reflectionsurface and side reflection surface being separately formed usingtransparent resin thereon. Thus, a proximity optical system to the lightemitting element can be formed.

In the above embodiments 2A to 2D, the reflection mirror 209 has acircular reflection shape to be formed by rotating, around the Z-axis,part of a parabola with a focal point at the origin of light emittingelement 206 and with a symmetry axis on the X-axis, and the radiationsurface 210 has a shape to compose part of a spherical surface centeredat the light emitting element 206. However, they are not specificallylimited thereto if they are formed to radiate light being emitted fromthe light emitting element 206 in the side surface direction.Especially, in the shape of transparent epoxy resin 208 in the aboveembodiments or when the relationship of H<R is established, thereflection mirror 209 is placed close to the light emitting element 206and thereby the same effect can be obtained in aspect of stabilizationof light distribution characteristic in LED based on the positionalprecision of optical system. Even when the relationship of H<R is notsatisfied, if h<1 mm, the same effect can be obtained.

Embodiment 3A

FIG. 37 shows an LED in embodiment 3A of the invention, wherein (a) is across sectional view thereof, and (b) is a plain view thereof.

As shown in FIG. 37, the LED 302 in embodiment 3A has an integratedstructure that a light emitting element 306 as a light source is sealedwith transparent epoxy resin 308 while forming optical surface. In theexplanation below, the center axis of light emitting element 306 is aZ-axis, a point on the top surface of light emitting element and on theZ-axis is an origin, and a coordinate system with an X-axis and a Y-axisorthogonal to the Z-axis at the origin is defined. Meanwhile, the Z-axisis also called center axis Z.

The LED 302 is composed such that the light emitting element 306 is, atthe origin, mounted through Ag paste on a lead frame 305 a of a pair oflead frames 305 a, 305 b that are of copper alloy and disposed through agap for insulation on the X-Y plane, the upper surface electrode oflight emitting element 306 is bonded through a gold wire 307 to the tipof lead frame 305 b, and part of lead frames 305 a, 305 b, lightemitting element 306 and wire 307 are sealed with transparent epoxyresin 308 (refractive index 1.55) while molding the optical surface.

The main feature of LED 302 is the shape of transparent epoxy resin 308.Namely, the transparent epoxy resin 308 has a central radiation surface309 a at the center of its upper surface (directly over the lightemitting element 306) and a reflection surface 309 b formed subsequentlyto the central radiation surface 309 a to compose a reflection mirror309.

The reflection surface 309 b has a circular reflection shape to beformed by rotating, around the Z-axis, part of a parabola with a focalpoint at the origin and with a symmetry axis on the X-axis. The centralradiation surface 309 a is an optical surface to radiate light to beemitted from the light emitting element 306 in the Z-axis direction andmay be formed concave or convex. According to use, the central radiationsurface 309 a may be not formed.

The reflection surface 309 b has a solid angle of 2π{1−cos θc} orgreater, where θc is a critical angle of the abovementioned transparentmaterial. Alternatively, an angle θ1 of an oblique line L1 to connectbetween the focal point of light emitting element 306 and the edge ofreflection surface 309 b to the Z-axis is set to be greater than (90degrees−θc).

A diameter W of the reflection surface 309 b is preferably less than φ10mm. This is because, when the transparent epoxy resin 308 has a largesize, though it is advantageous in optical design, a crack may begenerated due to a thermal shock by remaining stress in resin curing andtherefore the transparent epoxy resin 308 preferably has a small size.

The transparent epoxy resin 308 has a side radiation surface 310 tocompose part of a spherical surface centered at the origin. A height Hto vertically connect between the edge of reflection surface 309 b atthe reflection surface 310 and the X-axis to be horizontally extendedfrom the focal point of light emitting element 306 is set such that anangle θ2 to the X-axis of the oblique line L1 connecting between thefocal point of light emitting element 306 and the edge of reflectionsurface 309 b is less than the critical angle θc. The angle θ2 ispreferably less than (θc−5 degrees). This is because, even when anincident angle does not reach θc, the interface reflection is likely tooccur near θc as shown in FIG. 38.

Although the abovementioned (90 degrees−θc) or 2π{1−cos θc} means havinga large solid angle to the light emitting element 306, it also means arange that the interface reflection of light being directly irradiatedfrom the light emitting element 306 to the side radiation surface 310can be prevented in order not to be stray light. Even if the sideradiation surface 310 is a vertical surface with no taper, when θ1 isgreater than (90 degrees−θc), θ1 becomes less than θc and thereby nostray light due to total reflection is generated.

The LED 302 has such dimensions that the diameter is 10 mm, the diameterW of reflection surface 309 b is 9 mm, the height H of outer edge in theZ-axis direction, and the angle θ1 to the Z-axis of the line from thetop surface of light emitting element 306 to the edge of reflectionsurface 309 b is 70 degrees.

The lead frame 305 a with the light emitting element 306 mounted thereonis composed such that part of the lead frame 305 a embedded intransparent epoxy resin 308 is reduced as much as possible to the extentthat the wire 307 is not exposed, by drawing it out of transparent epoxyresin 308 under the mount surface from the vicinity of the mountposition of light emitting element 306. The lead frame 305 b is also inthe shape of a strip-like plate and is disposed parallel to part of thelead frame 305 a being drawn out of the resin.

Since the LED 302 of a type to radiate light in a directionperpendicular to the Z-axis, called side radiation type, requires a wideradiation range and sufficient radiation intensity, the light emittingelement 306 used is of large current type (high-output type).

For example, as shown in FIG. 39, it is composed of n-AlInGaP claddinglayer 312, layer 313 including a light emitting layer, AlInGaP claddinglayer 314 and p-GaP window layer 315 that are sequentially formed onn-GaP substrate 311. Further, an Al bonding pad (positive electrode) 317is formed through AuZn contact 316 for the ohmic contact with the windowlayer 315 on the p-GaP window layer 315. Further, Au alloy electrodes(negative electrodes) 228 are formed under the n-GaP substrate 311.

The light emitting element 306 with the negative electrodes 318 ismounted on the lead frame 305 a, and the positive electrode 317 thereofis bonded through the wire 307 to the tip of lead frame 305 b. Byapplying a predetermined voltage between the electrodes 317 and 318, thelight emitting element 306 emits light. The emission of light isgenerated such that carriers (electron and hole) are confined in thelayer 313 including the light emitting layer by the cladding layers 312,314 and the carriers are recombined in the layer 313 including the lightemitting layer.

The light emitting element 306 has a large heat release value since itis of large current type. In embodiment 3A, the lead frames 305 a, 305 bwhere to mount the light emitting element 306 are of a copper alloymaterial with a high thermal conductivity (300 W/m·k or higher) and theheat radiation property is enhanced by reducing the embedded portion asmuch as possible as shown in FIG. 37. Thus, by reducing heat to beaccumulated in the light emitting element 306 and lead frame 305 a asmuch as possible, the temperature rise of light emitting element 306 canbe suppressed and the reduction of light output in LED 302, which has anegative light output dependency to temperature, can be prevented.Therefore, the LED 302 can offer a high light output by setting a largesupply current. For example, a large amount of light can be obtained bysupplying a large current of more than 100 mA.

The emission operation of LED 302 thus composed will be explained below.

When a voltage is applied to the lead frames 305 a, 305 b of LED 302,the light emitting element 306 emits light. Of light to be emitted fromthe light emitting element 306, light emitted directly upward along theZ-axis from the light emitting element 306 is externally radiated fromthe central radiation surface 309 a while being directly transmittedthrough the transparent epoxy resin 308. Further, of light to be emittedfrom the light emitting element 306, light to reach the reflectionsurface 309 b is all subjected to total reflection due to its largeincident angle to the reflection surface 309 b, then heading to the sideradiation surface 310. Since the reflection surface 309 b has thereflection shape described earlier, light being reflected by thereflection surface 309 b is all radiated nearly in parallel with the X-Yplane. Since the side radiation surface 310 composes part of sphericalsurface centered at the light emitting element 306, the light beingradiated nearly in parallel is radiated forming nearly a plane indirections of 360 degrees around the Z-axis though it is slightlyrefracted by the side radiation surface 310.

FIGS. 40( a), (b) and (c) are characteristic diagrams showing a lightintensity distribution, a light flux distribution, and a light fluxintegration in a standard light emitting element. The lateral axisindicates an angle to the center axis, and the vertical axes indicatelight intensity ratio, light flux ratio and light flux ratio,respectively. Since θ1 of the outer edge to the Z-axis is 70 degrees,about 80% of light to be emitted from the light emitting element isreflected reaching the reflection surface 309 b, then radiated formingnearly a plane from the side radiation surface 310. The remaining partof about 20% is radiated in a direction of 70 degrees to the Z-axiswithout being refracted by the side radiation surface 310.

As described above, in the LED 302 of embodiment 3A, light to be emittedfrom the light emitting element 306 can be laterally radiated at anideal efficiency because: the light emitting element as a light sourceis sealed with transparent epoxy resin 308; the central radiationsurface 309 a, reflection surface 309 b and side radiation surface 310as optical surfaces are molded; and the reflection surface 309 b has ashape to be formed by rotating, around the center axis Z, part of aparabola with a focal point at the origin of light emitting element 306and with a symmetry axis on the x-axis.

Further, since the side radiation surface 310 of transparent epoxy resinis formed composing part of spherical surface centered at the lightemitting element 306, light being reflected by the reflection surface309 b and radiated nearly in parallel proceeds directly through the sideradiation surface 310 and then externally radiated forming nearly aplane in directions of 360 degrees around the Z-axis, and light directlyheading to the side radiation surface 310 from the light emittingelement 306 is externally radiated directly without being refracted bythe side radiation surface 310. Thus, since no light to be radiated inthe range of a small angle to the Z-axis exists, the radiationefficiency of light to be externally radiated in the lateral directionwhile being controlled as primary light from the side radiation surface310 can be significantly enhanced.

Further, since the side radiation surface 310 of transparent epoxy resin308 composes part of spherical surface centered at the light emittingelement 306, the side radiation surface 310 is in the shape of a taper.Therefore, the release from a die in potting mold or casting mold can befacilitated without breaking the transparent epoxy resin 308. In thecase of an inverted taper or vertical wall, the release from a diecannot be facilitated and the transparent epoxy resin 308 may be broken.Thus, it can be made by using a manufacturing method and resin materialgenerally available, and thereby its mass production property andstability in characteristic can be enhanced.

The side radiation surface 310 may be formed by using part of circularcone surface that is slightly inclined (e.g., a slope of about 4degrees) to the center of a cylinder, other than the spherical surface.Also in this shape, the release from a die can be facilitated withoutbreaking the transparent epoxy resin 308. Another shape to facilitatethe release from a die may be also used.

The LED 302 can be formed further low-profile by providing the centralradiation surface 309 a at the center of reflection surface 309 b, i.e.,directly over the light emitting element 306 and by curving thereflection surface 309 b from the circumference edge of centralradiation surface 309 a. If curved without forming the directly overplane, it is necessary to increase the distance between the lightemitting element 306 and the directly over plane and therefore thethickness increases that much. Such a disadvantage can be avoided byforming the directly over plane. The central radiation surface 309 a maybe convex or concave other than planar.

Since the central radiation surface 309 a is formed directly over thelight emitting element 306, light (vertical light) heading directlyupward of light to be emitted from the light emitting element 306 can beexternally radiated from the central radiation surface 309 a. Thus,light can be radiated from the entire radiation surface composed of thecentral radiation surface 309 a and the side radiation surface 310 inLED 302.

Since the diameter W of reflection surface 309 b is reduced to less thanφ10 mm, a crack due to a thermal shock by remaining stress in resincuring to be generated when the transparent epoxy resin 308 has a largesize can be eliminated.

According to use, the LED 302 may be not provided with the centralradiation surface 309 a. In this case, although light is not radiated inthe Z-axis direction, light to be emitted from the light emittingelement 306 can be, like the above manner, reflected in the direction ofside radiation surface 310 by the reflection surface 309 b.

Although the reflection surface 309 b has the circular reflection shapeto be formed by rotating, around the center axis Z, part of a parabolawith a focal point at the origin and with a symmetry axis on the x-axis,it may have a circular reflection shape to be formed by rotating, aroundthe center axis Z, part of a parabola with a symmetry axis of less than90 degrees to the Z-axis. With such a reflection surface, light will bealso reflected obliquely upward. The use of LED with this reflectionsurface is explained a modification in embodiment 3B as described later.

Further, the reflection surface 309 b may have a shape to be formed byrotating, around the center axis Z of light emitting element 306, partof an ellipse, a parabola or a hyperbola with a focal point at the lightemitting element 306 or in its vicinity. Still further, as shown by L2in FIG. 41, it may have a shape to be formed by rotating, around thecenter axis Z, part of lines to connect multiple points on a parabola.Further, it may be formed elliptic in viewing from the center axis Z,other than a shape to be formed by rotating around the center axis Z.Alternatively, anon axially-symmetrical shape may be used if it caneffectively laterally radiate light to be emitted from the lightemitting element 306.

Although the lead frames 305 a, 305 b are of copper alloy (thermalconductivity of 300 W/m·k or more), it may be of another material with ahigh thermal conductivity, which is not limited to 300 W/m·k or more.When the light emitting element 306 is not of large current type, it maybe of iron alloy etc.

FIG. 42( a) is a plain view showing an LED 302 a as a first modificationof the LED 302, and (b) is a cross sectional view thereof. As shown, theLED 302 a may be composed such that, of a pair of lead frames 322 a, 322b, the lead frame 322 a with the light emitting element 306 mountedthereon has a large area to enabled to widely diffuse heat of the lightemitting element 306 to prevent a crack at the boundary between the leadframe and transparent epoxy resin 308, and that a strip-like plate isextended from an edge of the wide area portion and drawn out of thetransparent epoxy resin 308 while being downward folded at the edgeportion to reduce the embedded portion in transparent epoxy resin 308 asmuch as possible. Although in FIG. 42 the wide area portion forms acircle with the counterpart, it may have any shape if it has a wide areato diffuse heat.

In the LED 302 a thus composed, since part of the lead frame 322 a thatis sealed with transparent epoxy resin 308 and on which the lightemitting element 306 is mounted has the wide area to widely diffuse heatof the light emitting element 306, even when the light emitting element306 is of large current type to have a large heat release value, heat tobe directly conducted from the light emitting element 306 to thetransparent epoxy resin 308 and heat to be conducted from the lightemitting element 306 through the lead frame 322 a to the transparentepoxy resin 308 can be diffused over the entire wide area lead frame 322a.

Further, the mount surface of lead frame 322 a where to mount the lightemitting element 306 can be used as a reflection surface to reflectlight to be emitted downward from the light emitting element 306. It isoptically advantageous.

FIG. 43 is a plain view showing an LED 302 b as a second modification ofthe LED 302.

As shown, the LED 302 b may be sealed with transparent epoxy resin 308after sealing the light emitting element 306 with transparent siliconresin 308 s in the shape of a small mold. In this case, since the lightemitting element 306 is first sealed with transparent silicon resin 308s in the shape of a small mold, the remaining stress can be furtherrelaxed and the lifetime can be prolonged. The transparent silicon resin308 s may have phosphor mixed therein and may be replaced by anothertransparent material.

Third to sixth modifications of the LED 302 may be composed as shown inFIG. 44, FIG. 45, FIG. 16 and FIG. 17, respectively.

FIG. 46 is a plain view showing an LED 302 g as a seventh modificationof the LED 302.

The LED 302 g is composed such that a reflection mirror 309 f is formedby disposing a separate circular reflection mirror 309 e around a nearlycylindrical reflection mirror 309 d with a diameter smaller than that ofthe basic reflection mirror 309. In making the reflection mirror 309 f,for example, a pair of the lead frames 305 a, 305 b (or lead frames 322a, 322 b) with the light emitting element 306 mounted thereon asdescribed earlier is set in a first resin sealing die, and thentransparent epoxy resin 308 a is injected thereinto and cured. Then, thereflection mirror 309 d formed by the curing is set in a second resinsealing die, and then transparent epoxy resin 308 b is injectedthereinto and cured. Thereby, the ring-shaped reflection mirror 309 e isformed. Alternatively, the nearly cylindrical reflection mirror 309 dand the ring-shaped reflection mirror 309 e may be formed separately,and the nearly cylindrical reflection mirror 309 d may be fitted in thering-shaped reflection mirror 309 e.

The shape of the reflection mirror 309 f thus formed is about the sameas that of the basic reflection mirror 309. Therefore, like the basicreflection mirror 309, the outer side surface of ring-shaped reflectionmirror 309 e composes part of a spherical surface centered at the lightemitting element 306. Although the boundary between the nearlycylindrical reflection mirror 309 d and the ring-shaped reflectionmirror 309 e is vertical as shown in this modification, it may be formedto compose part of a spherical surface centered at the light emittingelement 306, like the basic reflection mirror 309.

In the LED 302 g, the transparent epoxy resin to seal the light emittingelement 306, bonding wire 307 and a pair of lead frames 305 a, 305 b isdivided into the first and second transparent epoxy resins 308 a and 308b. Thereby, the volume of resin 308 a and 308 b becomes smaller thanthat of the basic transparent epoxy resin 308 and therefore eachremaining stress thereof can be reduced. Namely, even when heat isconducted from the light emitting element 306 or from the light emittingelement 306 through the lead frame 305 a to the transparent epoxy resin308 a, 308 b, the thermal expansion due to a remaining stress caused byheat can be reduced because each remaining stress is small and separate.Thus, a crack at the boundary between the light emitting element 306 andthe lead frame 305 a or transparent epoxy resin 308 a can be prevented.

Further, when the seventh modification that the reflection mirror iscomposed of divided transparent epoxy resins is applied to the LED asshown in FIG. 44, FIG. 45, FIG. 16 and FIG. 17, such a crack can beprevented as well.

Embodiment 3B

FIG. 47( a) is a plain view showing an LED light using the LED inembodiment 3B of the invention, (b) is a cross sectional view cut alongthe line A-A in (a), and (c) is an enlarged cross sectional view showingpart P in (b).

As shown in FIG. 47, the LED light 301 is composed such that the LED 302as shown in FIG. 37 is disposed at the center of a disk-like main bodyand a reflection mirror 303 with a concentric and stepwise reflectionsurface 303 a formed thereon is formed around the LED 302. Hereinafter,the reflection mirror 309 of LED 302 is called first reflection mirror309 and the above reflection mirror 303 is called second reflectionmirror 303.

The second reflection mirror 303 has the reflection surface 303 a thatis made by molding transparent acrylic resin and then by applyingaluminum evaporation thereon. The reflection surface 303 a is, as shownin FIG. 47( c), inclined about 45 degrees to the X-Y plane.

The emission operation of LED light 301 using the LED 302 thus composedwill be explained with reference to FIG. 47. When a voltage is appliedto the lead frames 305 a, 305 b of LED 302, the light emitting element306 emits light. Of light emitted from the light emitting element 306,light heading to the Z-direction, i.e., directly upward is radiated outof the transparent epoxy resin 308 from the central radiation surface,then transmitted through a transparent front plate (not shown) disposedon the LED light 301 to the outside. Of light emitted from the lightemitting element 306, light in the range of 60 degrees or more to theZ-axis is irradiated to the top surface as the first reflection surface,thereby subjected to total reflection due to its large incident angle tothe top surface, then heading to the side radiation surface. The topreflection surface has a shape to be formed by rotating, around theZ-axis, part of a parabola with a focal point at the light emittingelement 306 and with a symmetry axis on the X-axis. Therefore, light tobe reflected by the top reflection surface all proceeds parallel to theX-Y plane. Since the side radiation surface composes part of a sphericalsurface centered at the light emitting element 306, this light directlyproceeds in parallel and is externally radiated in directions of 360degrees around the Z-axis while forming about a plane. Further, lightbeing directly irradiated to the side radiation surface from the lightemitting element 306 proceeds straight without being refracted therebysince the side radiation surface composes part of a spherical surfacecentered at the light emitting element 306, then radiated externally.Light to be radiated in parallel with the X-Y plane from the LED 302 isreflected nearly in the Z-axis direction by the reflection surface 303 awith an inclination of about 45 degrees on the second 303, then radiatedexternally.

Thus, the large-area and low-profile LED light 301 is composed bycombining the LED 302 and the second reflection mirror 303. Further,instead of the LED 302, any of LED's 302 in the first to seventhmodifications may be used and the same effect can be obtained thereby.

In the LED light 301, it is preferable that the LED 302 is small ascompared to the second reflection mirror 303, though a comparativeexample is shown in FIG. 48( a) and (b). This is because in the LED 302only the center portion is apt to appear to be emission point o. Asshown in FIG. 48( a), in the case of the second reflection mirror 303with a small inner diameter, nearly the entire radiation surface appearsto radiate light. As shown in FIG. 48( b), in the case of the secondreflection mirror 303 with a large inner diameter, radiated lightappears to be thinned out.

By using the LED 302 with a small diameter, the LED light 301 can becomposed having the relationship between the LED 302 and the secondreflection mirror 303 as shown in FIG. 48( a). Therefore, nearly theentire radiation surface can be made to appear to radiate light.

If the second reflection mirror 303 with a large inner diameter as shownin FIG. 48( b) is used, nearly the entire radiation surface can be madeto appear to radiate light by using the LED 302 c in FIG. 44 or the LED302 d in FIG. 45.

A first modification, LED 302 h, of the LED light 301 is composed suchthat, as shown in FIG. 49, a ring-shaped lends 309 h is formed on thereflection mirror 309 b to allow part of light emitted from the lightemitting element 306 to be radiated upward other than the centralradiation surface 309 a. The LED 302 h may be used for the compositionin FIG. 48( b).

A second modification of the LED light 301 is an LED light 301 a asshown in FIG. 50. The difference of an LED 302 i used in the LED light301 a from the LED 302 is that its reflection surface 309 b has acircular reflection shape to be formed, around the center axis Z, partof a parabola with a focal point not centered at the light emittingelement 306. Thereby, although in the LED 302 light to be emitted fromthe light emitting element 306 is reflected nearly in parallel, the LED302 i allows light to be diffused. In this case, like the LED 302, lightis externally radiated from the side radiation surface 310 while beingcontrolled as primary light and as a result a light distribution asshown in FIG. 51 can be obtained. Meanwhile, it is necessary to have asecond reflection mirror 303 c with a height h1 greater than h in FIG.47( b). However, in the LED 302 i, the reflection surface may have asmall size to the light emitting element 306 unless total reflection orlarge interface reflection at the side surface is generated.

FIG. 38 shows a transmittance to an incident angle at the side radiationsurface 310. Near at 40 degrees as the critical angle θ c, the totalreflection is generated and the transmittance becomes 0%. Even at (θc−5degrees) or more, the influence of interface reflection is strong thoughthe total reflection is avoided. Therefore, the incident angle to sideradiation surface 310 is further desirably (θc−5 degrees).

In the LED light 301 a thus composed, light from the LED 302 h isefficiently radiated in the horizontal and oblique directions andreflected by the reflection surface 303 a of reflection mirror 303 c.Therefore, the LED light 301 a can be a lamp with depth effect. Also inthis case, by setting (90 degrees−θc), an effective external radiationwithout stray light loss is considered.

As a modification of the LED light 301, the second reflection mirror 303may be composed such that the emission points are scattered as shown inFIG. 18 or may be divided into fan-shaped sections with differentlengths to form a polygon as shown in FIG. 19. Further, as shown in FIG.13, a circular LED light is cut to form a square or a shape includingpart of square, and segments thus cut can be combined to form anintegrated LED light. Further, by using the LED light as shown in FIG.19, a vehicle lamp such as an automobile tail lamp or brake lamp asshown in FIG. 78 and FIG. 90 may be formed.

Embodiment 4A

FIG. 52( a) is a plain view showing an LED light using an LED inembodiment 4A of the invention, (b) is a cross sectional view cut alongthe line A-A in (a), and (c) is an enlarged cross sectional view showingpart P in (b).

As shown in FIG. 52( a), the LED light 401 of embodiment 4A is composedsuch that the LED 402 with a light emitting element 406 as a lightsource mounted therein is disposed at the center of a disk-like mainbody and a reflection mirror 403 with a concentric and stepwisereflection surface 403 a formed thereon is formed around the LED 402.

In the explanation below, the center axis of light emitting element 406is a Z-axis, a point on the top surface of light emitting element 406 tointersect with the Z-axis is an origin, and an X-axis and a Y-axis inthe horizontal direction are orthogonal to the Z-axis at the origin.

The LED 402 integrally includes a first reflection mirror to reflectlight emitted from the light emitting element 406, as described later.The reflection mirror 403 is called second reflection mirror 403.

The second reflection mirror 403 has the reflection surface 403 a thatis made by molding transparent acrylic resin and then by applyingaluminum evaporation thereon. The reflection surface 403 a is, as shownin FIG. 52( c), inclined about 45 degrees to the X-Y plane.

The composition of LED 402 will be explained below with reference toFIG. 53 and FIG. 54.

As shown in FIG. 53 and FIG. 54, the LED 402 is composed such that thelight emitting element 406 is, at the origin, mounted on a lead frame405 a with a strip-like plate bent into L-shape of a pair of lead frames405 a, 405 b that are disposed through a gap for insulation on the X-Yplane, the upper surface electrode of light emitting element 406 isbonded through a wire 407 to the tip of lead frame 405 b, and part oflead frames 405 a, 405 b, light emitting element 406 and wire 407 aresealed with transparent epoxy resin 408 to be formed planar and nearlycylindrical.

The feature of LED 402 is that: the light emitting element 406 is sealedwith transparent epoxy resin 408 (hereinafter simply called resin 408)to form the first reflection mirror as described later and thereby thelight emitting element 406 and the first reflection mirror areintegrated; and the lead frame 405 a with the light emitting element 406mounted thereon is composed such that part of the lead frame 405 aembedded in transparent epoxy resin 408 is reduced as much as possibleby drawing it out of transparent epoxy resin 408 while being bent underthe mount surface from the vicinity of the mount position of lightemitting element 406. The lead frame 405 b is in the shape of astrip-like plate and is disposed parallel to part of the lead frame 405a being drawn out of the resin.

The light emitting element 406 is of large current type (high-outputtype) as shown in FIG. 55 so as to keep the emission intensity of LED402 at a predetermined value while reducing the number as much aspossible and to increase an area to be visually recognized by radiationof each LED 402 to enhance the design quality. This type is about thesame as that descried in embodiment 3A referring to FIG. 39 and itsexplanation is omitted here.

The light emitting element 406 has a large heat release value since itis of large current type. Therefore, if the LED 402 is made by transfermolding that the pair of lead frames 420 a, 420 b in the form of astrip-like plate are, as shown in FIG. 56, horizontally opposed to eachother in transparent epoxy resin 408 and drawn out therefrom, the lengthof embedded part from the mount position to mount the light emittingelement 406 to the position where the transparent epoxy resin 408 isdrawn out increases. As the embedded part of strip-like plate increases,heat generated from the light emitting element 406 is difficult toradiate out of the resin 408, and the light emitting element 406 issubjected to high temperatures. Thus, the brightness lowers. Further,since the resin 408 has a coefficient of thermal expansion differentfrom the lead frames 420 a, 420 b, as the length of embedded partincreases, the releasing of the resin 408 from the lead frames 420 a,420 b, a crack in the resin 408 or the breaking of wire is likely to begenerated when subjected to a heat shock.

In embodiment 4A, as shown in FIG. 53, the lead frame 405 a with thelight emitting element 406 mounted thereon is bent downward in thevicinity of the mount position of light emitting element 406 to shortenthe embedded part. Thereby, the heat radiation property can be enhanced,and the releasing of the resin 408 from the lead frames 405 a, 405 b, acrack in the resin 408 or the breaking of wire when subjected to a heatshock can be prevented. Further, in order to enhance the heat radiationproperty, the lead frames 405 a, 405 b are of a material with a highthermal conductivity such as copper alloy.

The LED 402 is, as shown in FIG. 53 and FIG. 54, formed planar andnearly cylindrical, which is the shape of transparent epoxy resin 408. Acentral radiation surface 409 a is formed at the center (portiondirectly over the light emitting element 406) of top surface of the LED402, and a first reflection mirror 409 is formed subsequently to thecentral radiation surface 409 a and has an umbrella-like reflectionshape to be formed by rotating, around the Z-axis, part of a parabolawith a focal point at the origin of light emitting element 406 (thus, itis not a paraboloid). Hereinafter, the shape of reflection surface inthe first reflection surface 409 is called reflection shape.

The first reflection mirror 409 is made to have a diameter to allow mostof light emitted from the light emitting element 406 to be subjected tototal reflection in the horizontal direction. In this embodiment, it hassuch a diameter that light of 20 degrees or more to the Z-axis ofemitted light can reach the top surface 409 b. A side surface 410 of theLED 402 composes part of a spherical surface centered at the lightemitting element 406. The LED 402 thus composed is fixed at the centerof circular LED light 401.

The emission operation of the LED light 401 is about the same as thatdescribed in embodiment 3A and its explanation is omitted here.

In the LED 402, the lead frame 405 a with the light emitting element 406mounted thereon is bent downward in the vicinity of the mount positionof light emitting element 406 and drawn out of the transparent epoxyresin 408 to shorten the embedded part in the resin 408 as much aspossible. By thus bending downward the lead frame 405 a while drawing itout of the resin 408, the embedded part is significantly reduced ascompared to that in being protruded in the horizontal direction (X) ofresin 408 since the lower part of a horizontal plane formed extendingthe mount surface of light emitting element 406 in resin 408 isconsiderably thinner than the upper part of the horizontal plane.Thereby, the heat radiation property can be enhanced, and the releasingof the resin 408 from the lead frames 405 a, 405 b, a crack in the resin408 or the breaking of wire when subjected to a heat shock can beprevented by shortening the embedded part of lead frame 405.

Further, in order to enhance the heat radiation property, the leadframes 405 a, 405 b are of a material with a high thermal conductivity.Thereby, heat can be radiated more efficiently. Therefore, even whenlarge current is supplied to the light emitting element 406, a largeoptical output can be obtained without being affected by heatsaturation. Further, in this embodiment, light being laterally radiatedis reflected frontward by the reflection mirror. Thus, the low-profileLED light with an enlarged radiation area can be obtained. Since the LEDhas the large light output, sufficient brightness can be maintained evenwhen the radiation area is enlarged.

Alternatively, as shown in FIG. 57( a) and (b), an LED 402 a is composedsuch that, of a pair of lead frames 432 a, 432 b, the lead frame 432 awith the light emitting element 406 mounted thereon has a wide area toallow heat of the light emitting element 406 to be diffused widely, andthat a strip-like plate to connect the edge of wide area portion isformed and the strip-like plate is bent downward at the edge and drawnout of the resin 408 to reduced the embedded part in the resin 408 asmuch as possible. Although in FIG. 57 the wide area portion forms acircle with the counterpart, it may have any shape, such as rectangularand triangle, if it has a wide area to diffuse heat. However, since asharp edge may cause a crack, it is desired that it is processed to besmoothed.

In the LED 402 a thus composed, part of the lead frame 402 a with thelight emitting element 406 mounted thereon being sealed with thetransparent epoxy resin 408 has a wide area to allow heat of the lightemitting element 406 to be diffused widely. Therefore, even when thelight emitting element is of large current type and has a large heatrelease value, heat to be conducted from the light emitting element 406directly to transparent epoxy resin 408 and heat to be conducted fromthe light emitting element 406 through the lead frame 432 a to thetransparent epoxy resin 408 can be diffused over the entire lead frame432 a with the wide area. In addition to this, by shortening theembedded part of lead frame, the releasing of the resin 408 from thelead frames 432 a, 432 b, a crack in the resin 408 or the breaking ofwire when subjected to a heat shock due to the difference in coefficientof thermal expansion between the transparent epoxy resin 408 and thelead frames 432 a, 432 b can be prevented in the vicinity of the mountportion of light emitting element 406.

Further, as shown in FIG. 57( c), part of the lead frame 432 a beingdrawn out of the transparent epoxy resin 408 may be provided withmultiple fins 432 c to promote the external radiation of heat.

Modifications of the LED light 401 are as follows. The LED may bealtered to that shown in FIG. 44, FIG. 45, FIG. 16 and FIG. 17. Thesecond reflection mirror may be composed such that the emission pointsare scattered as shown in FIG. 18 or that it is divided into fan-shapedsections with different lengths to form a polygon as shown in FIG. 19.As shown in FIG. 13, a circular LED light may be cut to form a square ora shape including part of square, and segments thus cut can be combinedto form an integrated LED light. Further, by using the LED light asshown in FIG. 19, a vehicle lamp such as an automobile tail lamp orbrake lamp as shown in FIG. 78 and FIG. 90 may be formed.

Embodiment 5A

FIG. 58 and FIG. 59 show the composition of an LED 502 in embodiment 5Aof the invention. The light emitting element 506 has a large heatrelease value since it is of large current type. Therefore, if the leadframe 505 a with the light emitting element 506 mounted thereon is thinlike a typical one, then the light emitting element 506 and lead frame505 a are heated by thermal accumulation and a crack may be generated atthe boundary between there and the transparent epoxy resin 508.

In embodiment 5A, in order to prevent the crack at the boundary betweenthere and the transparent epoxy resin 508, the lead frame 505 a with thelight emitting element 506 mounted thereon has a such wide area thatheat of the light emitting element 506 can be widely diffused and partof the lead frame to be protruded from the transparent epoxy resin 508has such a wide area that heat can be radiated as much as possible. Thelead frames 505 a, 505 b are of a material with a high thermalconductivity such as copper alloy. Although, in embodiment 5A, the leadframes 505 a, 505 b form a circle to be combined with the counterpart,it may have any shape, such as rectangular and triangle, if it has awide area to diffuse heat to prevent a crack. However, since a sharpedge may cause a crack, it is desired that it is processed to besmoothed.

In the LED 502 thus composed, part of the lead frame 505 a with thelight emitting element 506 mounted thereon being sealed with thetransparent epoxy resin 508 has a wide area to allow heat of the lightemitting element 506 to be diffused widely. Therefore, even when thelight emitting element 506 is of large current type and has a large heatrelease value, heat to be conducted from the light emitting element 506directly to transparent epoxy resin 508 and heat to be conducted fromthe light emitting element 506 through the lead frame 505 a to thetransparent epoxy resin 508 can be diffused over the entire lead frame505 a with the wide area. The object of providing the lead frame 505 awith the wide area is to rapidly radiate heat remaining in thetransparent epoxy resin 508 while dispersing the influence of such heat.This is because heat generated at the light emitting element 506 ismainly radiated from a radiation plate extended out of the transparentepoxy resin 508. Therefore, it is desired that part of the lead frame505 a being protruded from the transparent epoxy resin 508 has a widearea.

In other words, part of the lead frame 505 a being protruded from thetransparent epoxy resin 508 is made to have an area enabled toexternally conduct heat as far as possible and, thereby, heat can beefficiently radiated out of the resin to promote the heat radiation.

Further, in order to enhance the heat radiation property, the lead frame405 a is of a material with a high thermal conductivity. Thereby, heatcan be radiated more efficiently. Therefore, even when large current issupplied to the light emitting element 506, a large optical output canbe obtained without being affected by heat saturation.

[Modification]

FIG. 60 shows a modification of the LED 502.

An LED 502 e is, as shown in FIG. 60, composed such that transparentepoxy resin with which the light emitting element 506, bonding wire 507and a pair of lead frames 505 a, 505 b are sealed is divided into firstand second transparent epoxy resins 508 a, 508 b. Thereby, the volume ofresin 508 a and 508 b becomes smaller than that of the basic transparentepoxy resin 508 and therefore each remaining stress thereof can bereduced. Namely, even when heat is conducted from the light emittingelement 506 or from the light emitting element 506 through the leadframe 505 a to the transparent epoxy resin 508 a, 508 b, the thermalexpansion due to a remaining stress caused by heat can be reducedbecause each remaining stress is small and separate. Thus, a crack atthe boundary between the light emitting element 506 and the lead frame505 a or transparent epoxy resin 508 can be prevented.

Further, when the above modification that the first reflection mirror iscomposed of divided transparent epoxy resins is applied to the LED asshown in FIG. 14 to FIG. 17, such a crack can be prevented as well.

Further, the second reflection mirror may be composed such that theemission points are scattered as shown in FIG. 18 or may be divided intofan-shaped sections with different lengths to form a polygon as shown inFIG. 19. Further, as shown in FIG. 13, a circular LED light is cut toform a square or a shape including part of square, and segments thus cutcan be combined to form an integrated LED light. Further, by using theLED light as shown in FIG. 19, a vehicle lamp such as an automobile taillamp or brake lamp as shown in FIG. 78 and FIG. 90 may be formed.

Embodiment 6A

An LED in embodiment 6A of the invention will be explained below withreference to FIG. 61 to FIG. 63.

At first, the composition of LED 602 in embodiment 6A is explained withreference to FIG. 61.

As shown in FIG. 61, the LED 602 is made by attaching a reflector 604 toan emission section 603. The emission section 603 is composed such that,of a pair of vertically disposed leads 605 a, 605 b, the lead 605 a hasa light emitting element 608 mounted thereon, and the light emittingelement 608 is electrically connected through a wire (not shown) withthe lead 605 b. The tip portion of leads 605 a, 605 b, the lightemitting element 608 and the wire are set in a die for resin sealing andthen sealed with transparent epoxy resin while being formed into a crosssection as shown in FIG. 61( b).

A small plane is formed at the center of the upper surface 603 a ofemission section 603. The reflection surface 603 a as two-dimensionalradiation surface is formed subsequently to the center plane and has anumbrella-like shape to be formed by rotating, around the Z-axis, part ofa parabola with a focal point nearly at the center of an emissionsurface of light emitting element 608 and asymmetry axis on the X-axis.The side surface of emission section 603 composes part of a sphericalsurface centered at the light emitting element 608. The diameter of LED602 is 5 mm. Light to be emitted upward from the light emitting element608 is reflected nearly in the horizontal direction by the reflectionsurface 603 a, radiated 360 degrees in a two-dimensional direction.Further, light to be emitted sideward from the light emitting element608 is radiated from the side surface, which composes part of sphericalsurface, to a two-dimensional direction.

The emission section 603 with the small diameter and two-dimensionalradiation has a good mass productivity and a high reliability, but it isoptically disadvantageous. So, the ring-shaped reflector 604 is attachedto the outer face of emission section 603. The reflector 604 is ofacrylic resin with about the same refractive index as the emissionsection 603 and is physically and optically bonded thereto by an opticalbinder. However, the physical bonding is not always needed. Since a gapbetween the emission section 603 and the reflector 604 is small and bothinterfaces are nearly in parallel, even if the optical binder is notused, the optical loss is small. Therefore, optical binder is not alwaysneeded.

Since the emission section 603 has the reflection surface 603 a whilesealing the light emitting element 608, the reflection surface 603 a canbe disposed close to the light emitting element 608. For example, it canbe disposed 0.3 mm like a height of wire. By disposing close thereto, alarge solid angle can be taken geometrically. Thus, it is opticallyadvantageous as compared to the case that the reflection surface 603 ais made of the other material.

The reflector 604 has the upper surface 604 a that is a curved surfaceformed subsequently to the upper surface 603 a of emission surface 603.Light to be emitted from the light emitting element 608 and thenreflected by the upper surface 604 a of reflector 604 is radiated nearlyin the horizontal direction and 360 degrees in a two-dimensionaldirection. The outer diameter of emission section 603 is φ5 and theouter diameter of reflector is φ20. The optical advantage of reflector604 attached is explained with reference to FIG. 62. As shown in FIG.62, in the case of emission section 603 only, only light at an angle ofless than θ1 from a vertical line passing through the center of lightemitting element 608 is radiated in the two-dimensional direction.However, by attaching the reflector 604, light at an angle of up to θ2from the vertical line can be also radiated in the two-dimensionaldirection. Thus, light to be radiated at an angle of θ1 to θ2 can bealso effectively in the two-dimensional direction.

Although a two-dimensional system in cross section is shown in FIG. 62,light with a solid angle of θ1 to θ2 is exactly radiated and asignificant effect can be obtained thereby.

A lamp using the LED 602 in embodiment 6A of the invention will beexplained with reference to FIG. 63. As shown in FIG. 63, the lamp 601using the LED 602 in embodiment 6A is composed such that the LED 602 asa two-dimensional radiation light source with a light emitting elementbuilt therein is disposed at the center, and that about 45 degreesobliquely formed portions 606 a of stepwise surface of a reflectionmember 606 disposed around the LED 602 compose a reflection surface. Afront cover lens 607 covering these parts is provided. When power issupplied through leads 605 to the LED 602, light from the light emittingelement is radiated 360 degrees in the two-dimensional direction fromthe side surface of reflector 604 being attached to around the emissionsection 603. The light is reflected by the reflection surface 606 a ofreflection member 606 nearly in the vertical direction and thenexternally radiated through the front cover lens 607.

Herein, the two-dimensional direction means a direction from the LED 602to the reflection surface 606 a of reflection member 606 disposed aroundthe LED 602. It is not strictly a planar direction perpendicular to theZ-axis from the LED 602 and means a direction that light from the LED602 can be efficiently radiated to the reflection surface disposedaround the LED 602.

Thus, the lamp 601 using the LED 602 in embodiment 6A is highlylow-file, and most of light to be radiated from the LED 602 can beeffectively utilized and efficiently radiated externally through thefront cover lens 607.

Embodiment 6B

An LED in embodiment 6B of the invention will be explained below withreference to FIG. 64.

As shown in FIG. 64, the LED 612 in embodiment 6B has about the sameemission section 603 as that in embodiment 6A. However, a reflector 614thereof has a bottom surface 614 b that is upward moved close to themount surface level of light emitting element 608 and the reflector 614is thus low-profile. Thereby, in addition to light to be upward radiatedfrom the light emitting element 608, light to be downward radiated fromthe side surface of light emitting element 608 is radiated in thetwo-dimensional direction from the side surface of reflector 614 whilebeing subjected to total reflection by the bottom surface 614 b ofreflector 614 since its incident angle to the bottom surface 614 b ofreflector 614 increases exceeding the critical angle.

Although light may be downward reflected by the upper surface 614 a ofreflector 614 without being reflected in the horizontal direction asshown in FIG. 64 since the light emitting element 608 has a size, suchlight can be also radiated from the side surface of reflector 614 in thetwo-dimensional direction while being subjected to total reflection bythe bottom surface 614 b of reflector 614.

Therefore, the amount of light to be radiated from the LED 612 in thetwo-dimensional direction increases, and the two-dimensional radiationLED with good radiation efficiency can be obtained.

Embodiment 6C

An LED in embodiment 6C of the invention will be explained below withreference to FIG. 65.

As shown in FIG. 65, the LED 621 in embodiment 6C has about the sameemission section 603 as that in embodiment 6A. However, a reflector 624thereof has a stepwise bottom surface that includes a reflection surface624 b at its oblique portion, and light to be radiated from the uppersurface 603 a, 624 a in the two-dimensional direction is upwardreflected by the reflection surface 624 b. Light being upward reflectedis subjected to refraction by the upper surface 624 a when it isexternally radiated through the upper surface 624 a of reflector 624.Thus, the reflection direction of reflection surface 624 a is controlledto allow light after refraction to be externally radiated nearly in thevertical direction. If the angle of reflection surface 624 b to thetwo-dimensional radiation light becomes an angle not causing totalreflection, then the reflection surface 624 b needs to be externallymirror-finished by metal evaporation etc. to secure a high reflectivity.

Thus, by forming the reflection surface 624 b to reflect thetwo-dimensional radiation light nearly in the vertical direction, theLED 621 serves as a small lamp.

Embodiment 6D

An LED in embodiment 6D of the invention will be explained below withreference to FIG. 66.

As shown in FIG. 66, the LED 631 in embodiment 6D has about the sameemission section 603 as that in embodiment 6A. However, a reflector 634thereof is elliptic while that of the above embodiments is circular. Thereflector 634 has, like embodiment 6C, a stepwise bottom surface thatincludes a reflection surface 634 b at its oblique portion, and light tobe radiated from the upper surface 603 a, 634 a in the two-dimensionaldirection is upward reflected by the reflection surface 634 b. Lightbeing upward reflected is subjected to refraction by the upper surface634 a when it is externally radiated through the upper surface 634 a ofreflector 634. Thus, the reflection direction of reflection surface 634a is controlled to allow light after refraction to be externallyradiated nearly in the vertical direction. If the angle of reflectionsurface 634 b to the two-dimensional radiation light becomes an anglenot causing total reflection, then the reflection surface 634 b needs tobe externally mirror-finished by metal evaporation etc. to secure a highreflectivity.

Further, as shown in FIG. 66( a), the bottom surface of reflector 634 isdivided into eight segments between neighboring segments of which thereflection surface 634 b is formed alternately. Each reflection surface634 b has a curvature according to a radiation density from the emissionsection 603 and, thereby, the entire LED 631 can have even brightness.As a result, in viewing from the top, the LED 631 can have an evenbrightness on the entire surface and can offer a natural feel withglitter. Further, the LED 631 can reflect external light even when it isturned off and thereby can offer a good appearance with glitter evenlyon the entire surface.

Embodiment 6E

An LED in embodiment 6E of the invention will be explained below withreference to FIG. 67.

As shown in FIG. 67, the LED 651 in embodiment 6E has a light sourcesection 653 and a reflection section 654 different from the aboveembodiments. The light source section 653 is composed such that, of apair of vertically disposed leads 655 a, 655 b, the lead 655 a has alight emitting element 608 mounted thereon, and the light emittingelement 608 is electrically connected through a wire (not shown) withthe lead 655 b. The tip portion of leads 655 a, 655 b, the lightemitting element 608 and the wire are set in a die for resin sealing andthen sealed with transparent epoxy resin while being formed into anintegrated shape of circular cone and cylinder as shown in FIG. 67. Thereflection section 654 is of acrylic resin with about the samerefractive index as transparent epoxy resin and is, at the center,provided with a recess corresponding to the cone portion of light sourcesection 653. It is, at the cone portion, physically and optically bondedthereto by an optical binder. However, the physical bonding is notalways needed. Since a gap between the light source section 653 and thereflection section 654 is small and both interfaces are nearly inparallel, even if the optical binder is not used, the optical loss issmall. Therefore, optical binder is not always needed.

The reflection section 654 has an upper surface 654 a to serve as atwo-dimensional reflection surface that light to be emitted from thelight emitting element 608 is reflected nearly in the two-dimensionalparallel direction. Thus, when power is supplied through the pair ofleads 655 a, 655 b and the light emitting element 608 emits light, lightto be upward emitted therefrom and then reflected by the upper surface654 a is reflected nearly horizontally 360 degrees in thetwo-dimensional direction, then externally radiated from the sidesurface of reflection section 654.

Thus, even without using the combination of emission section andreflector that have a two-dimensional reflection surface to reflectlight in a two-dimensional plane direction, the LED can radiate light athigh radiation efficiency in the two-dimensional direction. Thereflection section 654 is not always limited to one being formedcombined only to the cone portion of light source section 653 and may beformed also combined to the cylindrical portion of light source section653 extended below.

Although the LED in the above embodiments 6A to 6E uses a red lightemitting element, whatever color light emitting element it may use.Although the transparent material to seal the light emitting elementetc. in the emission section or light source section is transparentepoxy resin, the other material such as transparent silicon resin may beused.

The flat surface at the center of upper surface of emission section maybe concave or convex, or the reflection surface may be formed at thecenter. The reflection surface is not limited to a shape to be formed byrotating, around the Z-axis, part of a parabola with a symmetry axis onthe X-axis. Even when it has a shape to be formed by rotating, aroundthe Z-axis, part of an ellipse, a parabola, a hyperbola or itsapproximated curve with a focal point at the light emitting element orin its vicinity, light can be radiated in the predetermined range.

Although in the above embodiments the reflector and reflection sectionis circular or elliptic, they may have the other shape. Further,although the reflector and reflection section is of acrylic resin,whatever material they may use if it has about the same refractive indexas the sealing material of emission section.

The composition, shape, number, material, dimensions, connection formetc. of the other part in the LED are not limited to those described inthe above embodiments.

Embodiment 7A

A light emitting unit in embodiment 7A of the invention will beexplained below with reference to FIG. 68 and FIG. 70.

As shown in FIG. 68, the light emitting unit 701 in embodiment 7A has areflection plate 702, which composes its main body, that a reflectionsurface (optical control surface) 703 with different shapes is formedwith an angle of about 45 degrees declined to the center and its centerportion is at a bottom section 702 b with a level lower than a periphery702 a of the reflection plate 702. An LED 704 as a light source toradiate light in a plane direction is located at the center of bottomsection 702 b. Light to be radiated 360 degrees in the plane directionfrom the LED 704 is reflected by each reflection surface 703 and thenradiated toward over the sheet surface of FIG. 68.

The composition and radiation principle of LED 704 as shown in FIG. 70are about the same as those in embodiment 2 as shown in FIG. 26( a), (b)and its explanation is omitted here.

The light emitting unit 701 in embodiment 7A is low-profile, highlyefficient and can be applied to an odd-shaped lamp etc. As shown in FIG.68, light to be radiated 360 degrees in the plane direction from the LED704 and then reflected has different angle ranges depending on acircumference direction in light radiation. Namely, the optical controlsurface 703 to light radiated from the LED 704 has wide and narrowwidths. Therefore, even when asymmetrical in height and width, thecontrol of light distribution can be conducted simply by using thereflection plate 702. Further, since the LED 704 as a light source has areflection surface 709 being opposite to a light emitting element 706 toradiate light in the side direction of light emitting element 706, itcan radiate light in the plane direction by using the single package. Bydividing the optical control surface in circumference direction,radiation direction etc. from the light source, the reflection surfacecan be disposed at an arbitrary position. Thereby, the optical designcan be made based on reflected light and the design property can beenhanced.

Embodiment 7B

A light emitting unit in embodiment 7B of the invention will beexplained below with reference to FIG. 71.

As shown in FIG. 71, the light emitting unit 721 in embodiment 7B is anexample asymmetrical in height and width. Namely, its reflection plate722 has a trapezoidal shape that its left side is long and its shortright side is short. Like embodiment 7A, the reflection plate 722 has areflection surface (optical control surface) 723 with different shapesto be formed with an angle of about 45 degrees declined to the centerand its center portion is at a bottom section 722 b with a level lowerthan a periphery 722 a of the reflection plate 722. An LED 704 as alight source to radiate light in a plane direction is located at thecenter of bottom section 722 b. Light to be radiated 360 degrees in theplane direction from the LED 704 is reflected by each reflection surface723 and then radiated nearly perpendicularly toward over the sheetsurface of FIG. 71.

Even when the reflection plate 722 has such a shape, multiple opticalcontrol surfaces can be provided stepwise in one direction and thereflection surface can have a wide or narrow width depending on thedirection. Thus, on the right side with a narrow width of reflectionplate 722, the number of reflection surfaces in one direction isincreased by increasing the step number and the width of reflectionsurface is narrowed to increase the density of reflection surface.Thereby, the amount of reflected light per unit area on the right sideincreases and can be balanced with the amount of reflected light on theleft side.

Hence, in the light emitting unit 721 of embodiment 7B, even when thereflection plate 722 is asymmetrical in height and width, light can beradiated disposing the emission surface at a desired position.

Embodiment 7C

A light emitting unit in embodiment 7C of the invention will beexplained below with reference to FIG. 72 and FIG. 73.

As shown in FIG. 72 and FIG. 73, the light emitting unit 711 inembodiment 7C, like embodiment 7A, has a reflection plate 712, whichcomposes its main body, that a reflection surface (optical controlsurface) 713 with different shapes is formed with an angle of about 45degrees declined to the center and its center portion is at a bottomsection 712 b with a level lower than a periphery 712 a of thereflection plate 712. An LED 704 as a light source to radiate light in aplane direction is located at the center of bottom section 712 b. Lightto be radiated 360 degrees in the plane direction from the LED 704 isreflected by each reflection surface 713 and then radiated nearlyperpendicularly toward over the sheet surface of FIG. 72.

Different from embodiment 7A, as shown in FIG. 72, the reflectionsurface 713 is provided two or three steps around the LED 704 in eachdirection. Thus, the optical control surface 713 is provided at multiplepositions to a radiation direction from the light source.

Thereby, as shown in FIG. 72, the density of emission point 715A can beincreased significantly. The density of emission point 715A can be kepteven when the area of reflection plate is increased.

Thus, the light emitting unit 711 in embodiment 7C is low-profile,highly efficient and can be applied to an odd-shaped lamp withoutlowering the efficiency. Further, since the optical control surface isprovided at multiple positions to a radiation direction from the lightsource, it can be also applied to a shape with a large aspect ratio andthe density of emission point can be increased. Further, since light canbe also externally radiated from the central radiation surface 709 aformed at the center of LED 704, the center of LED 704 also becomesemission point and, therefore, the center of reflection plate can beavoided from being a dark point. Thus, the light emitting unit can offera good balance in distribution of emission point 715A.

Embodiment 7D

A light emitting unit in embodiment 7D of the invention will beexplained below with reference to FIG. 74.

A light source 714 of light emitting unit in embodiment 7D is disposedat the bottom section of a reflection plate like that shown inembodiments 7A to 7C. As shown in FIG. 74, the light source 714 iscomposed of a lamp-type LED 719 that a light emitting element 706 issealed with transparent epoxy resin 720, and a reflection mirror 716 oflight-transmitting material disposed above that. The reflection mirror716 is provided with a Fresnel lens 718 at the bottom.

The light source 714 thus composed is operated such that light to beemitted from the emission surface of light emitting element 706 isradiated from the LED 719 while being converged by the convex lens typetransparent epoxy resin 720 and is then irradiated to the Fresnel lens718 at the bottom of reflection mirror 716. Light to be converged nearlyvertically by the Fresnel lens 718 is subjected to total reflection by areflection surface 717 at the upper surface of reflection mirror 716being concaved in the shape of a circular cone, then radiated 360degrees nearly in the horizontal direction. The reason why the Fresnellens 718 is provided at the bottom of reflection mirror 716 is that,since the radiation efficiency lowers when the lens-type LED has a highlight convergence characteristic, the Fresnel lens is used together inorder to increase the effective light amount without increasing thelight convergence characteristic of LED 719.

Thus, the light source 714 in embodiment 7D can radiate planar light andthereby it can be used as a light source of light emitting unit, likethe LED 704 in embodiments 7A to 7C.

Embodiment 7E

A light emitting unit in embodiment 7E of the invention will beexplained below with reference to FIG. 75.

A light source 724 of light emitting unit in embodiment 7E is disposedat the bottom section of a reflection plate like that shown inembodiments 7A to 7C. As shown in FIG. 75, the light source 724 iscomposed of a reflection-type LED 728 that a light emitting element 706and a cup-shaped reflection mirror 729 are sealed with transparent epoxyresin 730, and a reflection mirror 726 of light-transmitting materialdisposed above that. The reflection mirror 729 of reflection-type LED728 is in the shaped of a paraboloid with a focal point at the lightemitting element 706.

The light source 724 thus composed is operated such that light to beemitted from the emission surface (bottom surface) of light emittingelement 706 is nearly vertically upward reflected by the paraboloidreflection mirror 729, then radiated from the LED 728 and irradiated tothe reflection mirror 726. Light to be nearly vertically entered theretois subjected to total reflection by a reflection surface 727 at theupper surface of reflection mirror 726 being concaved in the shape of acircular cone, then radiated 360 degrees nearly in the horizontaldirection. In this case, since the radiation efficiency is kept higheven when the light convergence characteristic is enhanced to convertradiation light of LED 728 into nearly parallel light, the effectivelight amount can be kept high without providing a Fresnel lens at thebottom of reflection mirror 726. Further, the reflection mirror 726 maybe bonded to the LED 728 through an optical binder so as not to generatethe interface reflection between the reflection surface of LED 728 andthe incident surface of reflection mirror 726. The LED 728 and thereflection mirror 726 may be integrally formed.

Thus, the light source 724 in embodiment 7E can radiate planar light andthereby it can be used as a light source of light emitting unit, likethe LED 704 in embodiments 7A to 7C.

Embodiment 7F

A light emitting unit in embodiment 7F of the invention will beexplained below with reference to FIG. 76.

A light source 734 of light emitting unit in embodiment 7F is disposedat the bottom section of a reflection plate like that shown inembodiments 7A to 7C. As shown in FIG. 76, the light source 734 iscomposed of eight small lamp-type LED's 735 that are similar to that inthe lamp-type LED 719 in embodiment 7D and that are arrayed circularlywhile having its light radiation surface toward outside. The smalllamp-type 735 is sealed to be formed thin and elliptic in cross sectionin a direction perpendicular to the sheet surface of FIG. 76. Therefore,the light source is operated such that light is not diffused in thedirection perpendicular to the sheet surface of FIG. 76 and that planarlight is radiated 360 degrees.

Thus, the light source 734 in embodiment 7F allows planar light to beradiated by the simple composition that the flat lamp-type LED's 735 arearrayed circularly and thereby it can be used as a light source of lightemitting unit, like the LED 704 in embodiments 7A to 7C.

Embodiment 7G

A light emitting unit in embodiment 7G of the invention will beexplained below with reference to FIG. 77.

A light source 744 of light emitting unit in embodiment 7G is disposedat the bottom section of a reflection plate like that shown inembodiments 7A to 7C. As shown in FIG. 77, the light source 744 iscomposed of eight small reflection-type LED's 745 that are similar tothat in the reflection-type LED 728 in embodiment 7E and that arearrayed circularly while having its light radiation surface towardoutside. The small reflection-type 745 is formed thin and flat in adirection perpendicular to the sheet surface of FIG. 77. Therefore, thelight source is operated such that light is not diffused in thedirection perpendicular to the sheet surface of FIG. 77 and that planarlight is radiated 360 degrees.

Thus, the light source 744 in embodiment 7G allows planar light to beradiated by the simple composition that the flat reflection-type LED's745 are arrayed circularly and thereby it can be used as a light sourceof light emitting unit, like the LED 704 in embodiments 7A to 7C.

Embodiment 7H

A lamp in embodiment 7H of the invention will be explained below withreference to FIG. 78.

As shown in FIG. 78, the lamp 741 in embodiment 7H is composed of thesix light emitting units in embodiment 7A. The six light emitting unitsare disposed two wide, three high in a lamp housing such that they areat different stages from each other and further in the back from thebottom toward the top. The top surface 701 a and side surface 701 b ofeach light emitting unit 701, and the inner wall 742 of housing of thelamp 741 are provided with smooth aluminum coating with a highreflectivity formed thereon.

Of light to be radiated from the light source of each light emittingunit, light inclined to some extent in the horizontal direction isirradiated to the top surface 701 a or side surface 701 b of lightemitting unit 701 or to the inner wall 742 of lamp 741 while being notreflected by its optical control surface. These surfaces have thealuminum coating with a high reflectivity formed thereon and thereforemost of light irradiated can be reflected thereby and radiated out ofthe lamp 741. Therefore, light of the lamp 741 can be visuallyrecognized even from outside the radiation range of lamp 741. Thus, thelamp 741 with a wide recognition range of light can be offered.

Embodiment 7I

A light emitting unit in embodiment 7I of the invention will beexplained below with reference to FIG. 79 and FIG. 80.

As shown in FIG. 79, the light emitting unit 743 in embodiment 7I hassuch a reflection surface that the position of an optical controlsurface 747 neighboring in the circumference direction is different fromeach other. Thereby, an oblique reflection surface 748 is formed sincepart of the side surface of optical control surface 747 is exposed.

As shown in FIG. 80, using such a reflection surface, the position of alight source 704 is displaced from the center. Thus, by displacing thelight source 704 from the center, light can be, as shown by arrows inFIG. 80, irradiated not only to the optical control surface 747 withhatched lines but also to the oblique reflection surface 748 on the sidesurface thereof. Therefore, when looking at the light emitting unit 743from outside the reflection direction of optical control surface 747,the reflection of light can be visually recognized at the obliquereflection surface 748 that the position of optical control surface 747neighboring in the circumference direction is different from each other.Thus, the light emitting unit with a large visual recognition angle canbe offered.

Although the LED in the above embodiments uses a red light emittingelement, whatever color light emitting element it may use. Although thetransparent material to seal the light emitting element etc. in LED istransparent epoxy resin, the other material such as transparent siliconresin may be used.

The composition, shape, number, material, dimensions, connection formetc. of the other part in the light emitting unit are not limited tothose described in the above embodiments.

Embodiment 7J

A light emitting unit in embodiment 7J of the invention will beexplained below with reference to FIG. 81 to FIG. 83.

As shown in FIG. 81, the light emitting unit 751 in embodiment 7J iscomposed such that a reflection plate 752 as a main body has a firstreflection surface 753 where reflection surfaces (optical controlsurfaces) 753 a, 753 b, 753 c, 753 d, . . . are formed that its anglesvary gradually such that a direction vector perpendicular to the opticalcontrol surface 753 a at the lowest position has the largest angle tothe Z-axis and a direction vector perpendicular to the optical controlsurface 753 d at the highest position has the smallest angle to theZ-axis, and that the reflection plate 752 has a center portion at itsbottom section 752 b one stage down its circumference 752 a. An LED 754as a light source to radiate planar light is disposed at the center ofbottom section 752 b. In operation, light to be radiated 360 degrees ina plane direction from the LED 754 is reflected by the first reflectionsurface 753, and then radiated in a direction oblique to the center axis(Z-axis) of light emitting element in the LED 754.

The composition and operation of LED 754 as shown in FIG. 82 are aboutthe same as those in LED of embodiment 2 as shown in FIG. 26, and itsexplanation is omitted here.

An application of the light emitting unit 751 to automobile rear lampwill be explained below with reference to FIG. 83. As shown in FIG. 83,even when the automobile rear lamp 763 is disposed at an inclinedsection 764 with a curvature in the backward and forward direction, itcan be disposed close to the inclined section 764 since the lightemitting unit 751 is low-profile and operable to radiate nearly parallellight in the oblique direction. Thereby, as compared to conventionalrear lamps, its mount space can be significantly saved and high externalradiation efficiency can be offered.

Thus, the light emitting unit 751 in embodiment 7J is low-profile, andcapable of being disposed along an inclined section and offering highexternal radiation efficiency.

Embodiment 7K

A light emitting unit in embodiment 7K of the invention will beexplained below with reference to FIG. 84.

As shown in FIG. 84, the light emitting unit 771 in embodiment 7K is,like embodiment 7J, composed such that an LED 754 as a light source toradiate planar light is disposed at the center of a board 772A as a mainbody. A transparent umbrella-shaped disk-like optical member 775 isdisposed around the LED 754 on the board 772A. The optical member 775has, at its bottom, reflection surfaces (optical control surfaces) 773a, 773 b, 773 c, 773 d, . . . that its angles vary gradually such that adirection vector perpendicular to the optical control surface 773 a atthe lowest position has the largest angle to the Z-axis and a directionvector perpendicular to the optical control surface 773 d at the highestposition has the smallest angle to the Z-axis. Further, the opticalmember 775 has a stepwise top surface, and a staircase surface 775 a inthe horizontal direction is nearly perpendicularly to the radiationdirection of light from the LED 754 to be reflected on the reflectionsurfaces 773 a, 773 b, 773 c, 773 d, . . . .

The light emitting unit 771 thus composed is operated such that light tobe radiated 360 degrees nearly in parallel with the X-axis directionfrom the LED 754 is entered to the optical member 775 and reflected bythe first reflection surface 773 upward in the vertical direction. Sincethe horizontal surface of stepwise top surface is nearly perpendicularto the vertical direction in FIG. 84, reflected light is directlyradiated in the vertical direction in FIG. 84 with high externalradiation efficiency, without being refracted by the optical member 775.

Thus, the light emitting unit 771 in embodiment 7K is low-profile, andcapable of being disposed along an inclined section and offering highexternal radiation efficiency. Although in embodiment 7K the firstreflection surface of optical member 775 gives total reflection, thefirst reflection surface 773 may have metal plating, metal evaporationetc. formed thereon.

Embodiment 7L

A light emitting unit in embodiment 7L of the invention will beexplained below with reference to FIG. 85.

As shown in FIG. 85, the light emitting unit 781A in embodiment 7L iscomposed such that a reflection plate 782A has a first reflectionsurface 783A that is an integration of multiple optical controlsurfaces. An LED 754 similar to that in embodiments 7J, 7K is disposedat the center of a bottom surface 782 a of the reflection plate 782A.The light emitting unit 781A in embodiment 7L is composed such that theangle and direction of each optical control surface is set to allowlight reflected by the multiple optical control surfaces to head to thesame direction. Herein, “angle” means an angle of planar light from theLED 754 as a light source to the light radiation surface and “direction”means an angle to the light radiation direction of LED 754.

For example, as shown in FIG. 85, even when the “angle” of opticalcontrol surface is 45 degrees, if the “direction” thereof is notperpendicular to the radius direction of LED 754 but inclined α degrees,then the direction of reflected light is slanted not directly over(toward over the sheet surface of FIG. 85). As a matter of course, thedirection of reflected light can be freely changed by changing the“angle” of optical control surface. By suitably setting the “angle” and“direction” of each optical control surface, light can be uniformlyreflected in a slanted direction. Thereby, the mount of light in thatdirection increases a great deal and, therefore, the external radiationefficiency increases.

Although the LED in the above embodiments uses a red light emittingelement, whatever color light emitting element it may use. Although thetransparent material to seal the light emitting element etc. in LED istransparent epoxy resin, the other material such as transparent siliconresin may be used.

The composition, shape, number, material, dimensions, connection formetc. of the other part in the light emitting unit are not limited tothose described in the above embodiments.

Embodiment 7M

An automobile combination lamp in embodiment 7M of the invention will beexplained below with reference to FIG. 86.

As shown in FIG. 86, the combination lamp 800 is composed such that, ina cover 801 that is open from a front surface in a direction shown by anarrow Z to a side surface in a direction shown by an arrow X and has ahollow interior, two partition plates 802 are disposed horizontally andin parallel to divide the interior into three levels at equal intervals,and three bases 803 are laterally arrayed at each level, and an LE light701A is attached to the front side of each base 803. Aluminumevaporation is formed on the ceiling surface 801 a, bottom surface 801 band side surface 801 c in the interior wall of cover 801, on the topsurface 802 a and bottom surface 802 b of partition plate 802, and onthe top surface 803 a and side surface 803 b of base 803. In otherwords, the interior of cover 801 is all formed of aluminum evaporation.

As shown in FIG. 87, which is a cross sectional view cut along the lineC-C in FIG. 86, each LED light 701A is composed of a combination of LED704 and reflection mirror 703. The LED 704 is attached to an LEDattachment board 810. The LED attachment board 810 is, as shown in FIG.88 as a perspective view, such composed that it has a shapecorresponding to the back side of bases 803 that are arrayedthree-levels, three-rows in the cover 801, and that two separate wiringpatterns 811 a, 811 b formed by evaporation of aluminum, copper etc. areformed in parallel at each level. A pair of lead frames 705 a, 705 b iswelded to the wiring patterns 811 a, 811 b. The LED attachment board 810with the wiring patterns 811 a, 811 b formed thereon has a symmetricalstructure.

The lead frames 705 a, 705 b are attached positioned corresponding tothe LED 704 to be protruded through a penetration hole at the center ofeach reflection mirror 703 as shown in FIG. 87. They are fixed as shownin FIG. 89. Namely, a cranked LED attachment 813 of insulating materialis fixed at a predetermined position in the LED attachment board 810,and the lead frames 705 a, 705 b can be positioned corresponding to thepenetration hole of reflection mirror 703 by fitting them in the concaveportion of LED attachment 813. After the fixing, the lead frames 705 a,705 b are welded to the wiring patterns 811 a, 811 b.

Then, the LED attachment board 810 thus made by welding is, as shown inFIG. 87, placed at the back side of cover 801 and moved forward whilepositioning the LED 704 at the penetration hole of each reflectionmirror 703. Thereby, the attachment is completed. Thus, the attachmentcan be conducted easily.

The composition and radiation principle of LED light 701A are about thesame as those in embodiment 4 as shown in FIG. 52 and its explanation isomitted here.

In this embodiment, light directly radiated from the light source (LED704) is radiated without being blocked on the way as in the conventionalone and, further, radiated light is efficiently reflected by all theinner surface of cover 801. Therefore, the combination lamp 800 can havean increased brightness, and the visibility of light not only in theback direction of automobile but also in the vertical and lateraldirections thereof can be enhanced.

Embodiment 7N

An automobile rear combination lamp 800A in embodiment 7N of theinvention will be explained below with reference to FIG. 90. Likecomponents are indicated by the same numerals used in embodiment 7M andits explanation is omitted.

The combination lamp 800A is composed such that three LED lights 701A,each of which is formed elliptic and has a second reflection mirror 703as a peripheral reflector and LED 704, are laterally disposed into anarray and three arrays are vertically disposed while being fixed to abase 803. The rear combination lamp has a cover 801 of transparent resinon the front side. The cover 801 has a light reflection surface formedby aluminum evaporation at the interior.

FIG. 91 is a cross sectional view cut along the line J-J in FIG. 90. TheLED light 701A is disposed such that its part is overlapped in its depthdirection (Z direction), and an LED light 701A on the left is disposedforward of an LED light on the right.

The second reflection mirror 703 is composed such that multiplereflection surfaces are concentric disposed around the LED 704.

The LED 704 is electrically connected to an attachment board disposedbehind and is disposed at a predetermined position to the secondreflection mirror 703.

In embodiment 7N, since the multiple elliptic LED lights 701A aredisposed overlapped in the depth direction in the cover 801, a novelvisual appearance can be obtained based on the reflection pattern whenthe LED light 701A is turned on. Even when the LED light 701A is notturned on (e.g., at noon), light to be entered through the cover 801from outside is reflected by the light reflection surface including thesecond reflection mirror 703 of rear combination lamp and, thereby, anovel visual appearance with a depth feel can be offered. Meanwhile, thenumber and arrangement of LED light 701A are not limited to those asshown. The same is equally true of the disposition thereof. For example,an LED light 701A at the center of an array may be disposed forward orbackward of the two neighboring LED lights 701A.

Since the light distribution characteristic of lamp can be secured bythe optical control based on reflection of the second reflection mirror703 without using another optical part such as a lens, the cover 801 canhave a plain structure and therefore light with a transparent feel canbe radiated in operation. Even when not in operation, the interior ofcover 801 can be seen and therefore a novel visual appearance can beobtained based on the shape of the second reflection mirror 703. Thecover 801 may be colorless, or colored, e.g. in red, yellow, orange etc.

Alternatively, the light distribution characteristic of lamp may becontrolled by using another optical part such as a lens. For example,the cover 801 may have a lens formed at its transparent portion.

Embodiment 7P

FIG. 92 is a cross sectional view showing an automobile rear combinationlamp 800B in embodiment 7P of the invention.

The LED light 701A is, like embodiment 7J, composed that a secondreflection mirror 703 with reflection surfaces 703 a, 703 b, 703 c and703 d formed to radiate light with an inclination to the center axisdirection of a light emitting element (not shown) in LED 704 is disposedalong the inner surface of a cover 801. Although in FIG. 92 the secondreflection mirrors 703 of LED light 701A are integrally formed, thesemay be separately formed along the inner surface of cover 801. The othercomposition is about the same as that in embodiment 7J, and likecomponents are indicated by the same numerals used in embodiment 7J andits explanation is omitted.

In embodiment 7P, since the LED light 701A is disposed along the innersurface of cover 801, the low-profile rear combination lamp 800B can beoffered while reducing the amount of protrusion to the body side.

Embodiment 8A

A lamp in embodiment 8A of the invention will be explained withreference to FIG. 93 to FIG. 96.

As shown in FIG. 93, the lamp 901 of embodiment 8A is composed such thatan LED 903 as a light source with a light emitting element built thereinis disposed at the center, and a reflector main body 904 is composed ofreflectors 904 a, 904 b that are each composed of a plurality ofsegments 905 a, 905 b as shown by hatched regions. As shown in FIG. 93(b), the reflectors 904 a, 904 b have the segments 905 a, 905 b with aslope of about 45 degrees, and they upward reflect light being reflectedin the two-dimensional direction by an optical surface 909 b opposite tothe emission surface of light emitting element 902 in LED 903.

Herein, two-dimensional direction means a direction from the LED 903 tothe reflection surface of reflectors 904 a, 904 b with the segments 905a, 905 b disposed around the LED 903. It is not strictly a planardirection perpendicular to the Z-axis from the LED 903 and means adirection that light from the LED 903 can be efficiently radiated to thereflection surface disposed around the LED 903.

The reflector 904 a at the inner circumference is close to the LED 903,the segments 905 a of reflector 904 a are all formed planar, and theeight segments 905 a form a regular octagon. In contrast, the segments905 b of reflector 904 b at the outer circumference are, as shown inFIG. 94, formed slightly concave in an A-A cross section thereof.

The composition and radiation principle of LED 903 are about the same asthose of LED in embodiment 1A as shown in FIG. 12 or in embodiment 2A asshown in FIG. 26, and its explanation is omitted here.

Since the reflector 904 a with a slope of about 45 degrees is around theLED 903, light reflected by the top surface 909 b is nearly in parallelwith the X-Y plane and light directly radiated from the side surface 910is about in parallel with the X-Y plane, light reflected by thereflector 904 a proceeds upward nearly vertically and is externallyradiated at least in the range of 20 degrees from the Z-axis. Althougheven light represented as “parallel” in the above explanation is notperfectly parallel since the light emitting element 902 has a size, anylight thereof is radiated nearly in parallel and is surely included atleast in the range of 20 degrees from the Z-axis.

On the other hand, although light radiated in the two-dimensionaldirection from the LED 903 is also reflected by the reflector 904 b atthe outer circumference, since the reflector 904 b is concaved in thelongitudinal direction as described above, such light is upwardreflected while being converged and enhanced in brightness. Thereby,although the intensity of light is attenuated in reverse proportion tothe square of a distance from the light source, reflected light of thereflector 904 a with a small attenuation ratio due to being not distantfrom the light-source LED 903 is upward reflected without beingconverged by the plane reflector 904 a. In contrast, reflected light ofthe reflector 904 b with a large attenuation ratio due to being distantfrom the light-source LED 903 is upward reflected while being convergedby the concave reflector 904 b. Meanwhile, light externally radiated inthe Z-axis direction from the central radiation surface 909 a at thecenter of LED 903 is directly radiated externally without beingirradiated to the reflector 904 disposed around the LED 903.

Since the light emitting element is LED to covert electric energydirectly into optical energy, no part thereof becomes hot like afilament of bulb. Further, since the size of light emitting element isvery small, the optical control efficiency can be enhanced. Further,since the LED itself has the reflection mirror to radiate light from thelight emitting element in the two-dimensional direction and thisreflection mirror is molded sealing the light emitting element withtransparent epoxy resin, the number of parts is decreased as compared toconventional LED's. It is made easier to conduct the positioning betweenthe light emitting element and the reflection mirror to radiate light inthe two-dimensional direction. Thus, a high precision in positioning canbe obtained easily.

As a result, in viewing from the top (from a distant position in theZ-axis direction), direct light from the LED 903 and radiated light fromthe segments being controlled of convergence allow the entire lamp 901to have an even brightness and a natural feel with glitter. Further, thelamp 901 can reflect external light even when it is turned off andthereby can offer a good appearance with glitter evenly on the entiresurface.

Modifications of the lamp 901 in embodiment 8A will be explained belowwith reference to FIG. 95 and FIG. 96. One modification in FIG. 95 iscomposed such that the segment 905 b of reflector 904 does not have aconcave surface in A-A direction and has a concave surface in B-Bdirection. Another modification in FIG. 96 is composed such that thesegment has a concave surface in both directions. Both modificationsneed a convergence characteristic at the outer reflector 904 b.

Alternatively, the inner segment 905 a may be formed convex and theouter segment 905 b may be formed planar, thereby allowing the innerreflected light to be diffused to equalize the entire brightness. Thismodification is suitable for the case that a wider light distributionthan the lamp 901 of embodiment 8A is needed or the case that the solidangle of reflector segment to the light source is small. Furthermodifications are that three ring-like reflectors are provided as aconvergence reflection surface or a diffusion reflection surface whilechanging the curvature according to a radiation density from the lightsource to each segment, and that the number of segments in the outerreflector is greater than that in the inner reflector. For example, theouter reflector 904 b may have a higher brightness than the reflectorclose to the LED 903.

Thus, the lamp of this embodiment can be low-profile, highly efficient,and can have a large degree of freedom in appearance, an even brightnesson the entire surface and a natural feel with glitter.

Embodiment 8B

A lamp in embodiment 8B of the invention will be explained withreference to FIG. 97.

As shown in FIG. 97, the lamp 911 of embodiment 8B is composed such thatthe distance from the center is differentiated between laterallyneighboring segments. Namely, around the LED 903 as a light source likethat in embodiment 8A, segments 915 a disposed at the nearest position,segments 915 b alternately disposed at the next position, segments 915 calternately disposed at the next position, and segments 915 dalternately disposed at the next position, thus, being step by stepdistant from the LED 903. By thus disposing the segments 915 a, 915 b,915 c and 915 d of reflector, the luminescent point of lamp 911 can befurther dispersed. Further, by allowing the segments 915 a, 915 b, 915 cand 915 d to have a curvature according to the radiation density fromthe LED 903, the entire lamp 911 can have an even brightness.

The neighboring segments need not to be perfectly alternately disposedas descried above, they may be displaced each other to some extent(e.g., about half the width of segment). Even in this case, theluminescent point of lamp 911 can be dispersed to some extent.

Embodiment 8C

A lamp in embodiment 8C of the invention will be explained withreference to FIG. 98.

As shown in FIG. 98, the lamp 921 of embodiment 8C is composed such thata nearly elliptic radiation surface is formed by reflector segments 922arrayed at two stages. The LED 903 as a light source like that inembodiment 8A is disposed at the center, and the segments 922 arearrayed at two stages around the LED 903 to form an ellipse. Further, byallowing the segments 922 to have a curvature according to the radiationdensity from the LED 903, the entire lamp 921 can have an evenbrightness.

Thus, the lamp of this embodiment can be low-profile, highly efficient,and can have a large degree of freedom in appearance, and can be appliedto an irregular shape such as ellipse without reducing the efficiency.

Embodiment 8D

A lamp in embodiment 8D of the invention will be explained withreference to FIG. 99.

As shown in FIG. 99, the lamp 931 of embodiment 8D is composed such thatan ellipse is formed by segments 932 but the position of LED 903 as alight source is displaced from the center. Thereby, although theposition of each segment is also various, the entire lamp 931 can havean even brightness by allowing the segments 932 to have a curvatureaccording to the radiation density from the LED 903. If an evenradiation is given in the two-dimensional direction, the radiationdensity to each segment is in reverse proportion to the square of adistance from the light source to each segment. As described in earlierembodiment, in this embodiment 8D, the ratio in distance between asegment close to the light source and a segment distant therefrom islarge and, therefore, a big difference between the radiation densitiesis generated. However, by making the segment convex, and by sequentiallydecreasing the curvature according to the distance and making the mostdistant segment planar, the brightness can be equalized.

Although in the above embodiments the brightness is equalized on theentire lamp by providing the segment with a curvature, the brightnessmay be not only equalized but also changed according to position. Inbrief, it is important that the brightness of lamp can be controlled byproviding the segment with a curvature.

Embodiment 8E

A lamp in embodiment 8E of the invention will be explained withreference to FIG. 100.

As shown in FIG. 100, the lamp 941 of embodiment 8E is composed suchthat a disk-like transparent member 944 is disposed around an LED 943.The LED 943 is, different from the LED 903 in the above embodiments,composed such that a light emitting element 942 is mounted on the topsurface of a lead 946 a of a pair of leads 946 a, 946 b verticallydisposed, the light emitting element 946 is electrically connectedthrough a wire to the lead 946 b, and these components are resin sealedinto a shape like that of the LED 903. Also in the above embodiments,the LED 943 may be used instead of the LED 903.

Reflectors 945 are formed at three stages on the bottom surface oftransparent member 944. The reflectors 945 are operated such that lightbeing radiated in the two-dimensional direction from the LED 943 andthen transmitted through the transparent member 944 is upward reflectedby its total reflection. Each stage thereof is divided into eightsegments, a segment with a high radiation density from the LED 943 beinglocated nearby is set to have a low convergence characteristic, and asegment with a low radiation density from the LED 943 being located faris set to have a high convergence characteristic. Thereby, the lamp canhave a balanced brightness and an even light radiation on the entirereflector.

Embodiment 8F

A lamp in embodiment 8F of the invention will be explained withreference to FIG. 101.

As shown in FIG. 101( a), the lamp of embodiment 8F is composed suchthat, instead of the integrated type LED 903, 943, a radiation lightsource 962 is used that eight lens-type LED's 963 as a light source aredisposed in the shape of an octagon while facing its radiation surfacein the two-dimensional direction. As shown in FIGS. 101( b), (c) and(d), the lens type LED 963 has a sealing resin lens 964 that is wide inβ direction and narrow in γ direction perpendicular thereto. Theradiation light source 962 is composed such that the eight lens-typeLED's 963 are arranged allowing its α-β plane to be located in thetwo-dimensional direction.

The lens-type LED 963 generate slightly diffused radiation light in βdirection and nearly parallel radiation light in α direction. Thus, theradiation light source 962 can radiate light 360 degrees withoutinterruption in the two-dimensional direction. If there is a bigdifference in distance to each reflector segment to be disposed aroundthe radiation light source 962, the same effect as the above embodimentscan be obtained.

Embodiment 8G

A lamp in embodiment 8G of the invention will be explained withreference to FIG. 102.

As shown in FIG. 102( a), the lamp of embodiment 8G is composed suchthat, instead of the integrated type LED 903, 943, a radiation lightsource 952 is used that eight reflection-type LED's 953 as a lightsource are disposed in the shape of an octagon while facing itsradiation surface in the two-dimensional direction. As shown in FIGS.102( b) and (c), the reflection type LED 953 is composed such that alight emitting element 942 is mounted on the tip back surface of a lead954 a of a pair of leads 954 a, 954 b, the light emitting element 942is, at its top terminal, electrically connected through a wire to thelead 954 b, a reflection mirror 955 with a shape of paraboloid isdisposed facing the emission surface of light emitting element 942, andthese components are resin sealed with transparent epoxy resin 956. Inoperation, light emitted from the light emitting element 942 isreflected nearly in parallel with the perpendicular axis direction bythe reflection mirror 955 with the shape of paraboloid, then externallyradiated from a radiation surface 957. Thus, by using the reflectiontype structure, light emitted from the light emitting element can bemore efficiently radiated in the two-dimensional direction.

When light of light emitting element 942 is reflected accurately in theperpendicular axis direction by the reflection mirror 955, portion withno radiated light may be generated between neighboring reflection typeLED's 953 in the radiation light source 952. However, since, in fact,light externally radiated in an oblique direction due to the size etc.of the light emitting element 942 is generated, the radiation lightsource 952 can radiate light 360 degrees without interruption in thetwo-dimensional direction. If there is a big difference in distance toeach reflector segment to be disposed around the radiation light source962, the same effect as the above embodiments can be obtained. Althoughthe light source is not low-profile, downsized as compared to that inthe above embodiments, such a light source may be used practically.

Although the LED in the above embodiments uses a red light emittingelement, whatever color light emitting element it may use. Although thetransparent material to seal the light emitting element etc. in LED istransparent epoxy resin, the other material such as transparent siliconresin may be used.

The composition, shape, number, material, dimensions, connection formetc. of the other part in the lamp are not limited to those described inthe above embodiments.

INDUSTRIAL APPLICABILITY

As described above, a light emitting diode (LED) of the inventioncomprises:

a light emitting element mounted on a power source supply means;

a sealing means of a transparent material to seal the light emittingelement;

a reflection surface that is opposite to an emission surface of thelight emitting element and reflects light emitted from the lightemitting element in a direction orthogonal to the center axis of thelight emitting element or in a direction at a large angle to the centeraxis; and

a side radiation surface that sideward radiates light reflected by thereflection surface in a direction orthogonal to the center axis of thelight emitting element or in a direction at a large angle to the centeraxis.

Thus, by the transparent material, the center axis of reflection surfaceand side radiation surface as optical surfaces can be precisely formedwhile being coincided with the center axis of light emitting unit.Therefore, the potential problem of conventional LED light, where thereflection mirror is provided outside the LED with the dome section toconverge light, can be solved that the structure of light source itselfmay cause a difference in light distribution characteristic and, inaddition, a difference in light distribution characteristic may begenerated due to a deviation in position between the LED and thereflection mirror provided outside the LED.

Since the light emitting unit is integrally sealed by the transparentmaterial, a deviation in position does not occur even when beingsubjected to a physical shock after the manufacture. Since no interfaceexists between the light emitting element and reflection surface, astain etc. does not invade and, therefore, loss of light is notgenerated due to the interface and stain etc. Further, since the lightemitting element is directly sealed in the transparent material, theentire thickness can be decreased and the feature of LED, low-profile,can be utilized to the utmost.

By providing a central radiation surface at the center of the reflectionsurface to radiate light emitted from the light emitting element in adirection nearly parallel to the center axis of the light emittingelement, light upward radiated from the light emitting element can bedirectly taken out. Therefore, the appearance can be enhanced since thecenter of light emission is not blacked out.

By composing such that the central radiation surface is formed in therange of 0.3 mm to 1.0 mm from the element emission surface in thecenter axis direction of light emitting element, the solid angle ofreflection surface can be increased to enhance the opticalcharacteristic. In addition, even when the reflection surface is closeto due to the central radiation surface, the bonding space in wirebonding and the space for resin mold can be secured.

By composing such that the central radiation surface has an area smallerthan the emission area of the light emitting element, when a reflectionmirror is provided around the light emitting element, the reflectionintensity by reflection mirror can be balanced to the radiationintensity from central radiation surface. Thus, the appearance can beenhanced.

Further, a light emitting diode (LED) of the invention comprises:

a light emitting element mounted on a power source supply means; and

a sealing means of a transparent material to seal the light emittingelement;

wherein the sealing means comprises: a reflection surface that reflectslight emitted from the light emitting element in a direction orthogonalto the center axis of the light emitting element or in a direction at alarge angle to the center axis; and a side radiation surface thatsideward radiates light reflected by the reflection surface; and thereflection surface has a shortest distance from the light emittingelement of less than ½ a radius R of the reflection surface so as toform a proximity optical system.

In this composition, light from the light emitting element can beradiated not only in the center axis direction but also in the directionorthogonal to the center axis while making the LED low-profile, and,since the radiation to the direction orthogonal to the center axisincreases according as the reflection surface comes close to the lightemitting element, a light distribution characteristic with a wideradiation range can be obtained. Further, even when using a light sourcewith a deviation in light distribution characteristic of light emittingelement, no difference in brightness on the surface of LED light occurssince light is radiated in a wide radiation range.

Further, a light emitting diode (LED) of the invention comprises:

a light emitting element mounted on a power source supply means; and

a sealing means of a transparent material to seal the light emittingelement;

wherein the sealing means comprises: a reflection surface that reflectslight emitted from the light emitting element in a direction orthogonalto the center axis of the light emitting element or in a direction at alarge angle to the center axis; and a side radiation surface thatsideward radiates light reflected by the reflection surface; and thereflection surface is formed such that its radius R is greater than aheight H from the emission surface of the light emitting element to anedge of the reflection surface in the center axis direction of the lightemitting element so as to form a proximity optical system.

In this composition, light from the light emitting element can beradiated not only in the center axis direction but also in the directionorthogonal to the center axis while making the LED low-profile. Thus, alight distribution characteristic with a wide radiation range can beobtained.

By composing such that, in the LED, the light emitting element has aradiation intensity I(θ) represented by: I(θ)=k·cos θ+(1−k)·sin θ at anemission angle θ of emitted light to the center axis direction, where kis a constant to be determined by a radiation intensity according to theemission angle θ of the light emitting element, and k≦0.8 is satisfied,light from the light emitting element can be radiated not only in thecenter axis direction but also in the direction orthogonal to the centeraxis while making the LED low-profile. Thus, a light distributioncharacteristic with a wide radiation range can be obtained.

By composing such that, in the LED, the light emitting element comprisesa transparent substrate to have a light transmitting property to lightemitted therefrom, reflected light in the light emitting element can beexternally radiated. Thus, the radiation efficiency can be enhanced.

By composing such that, in the LED, the sealing means comprises a lightdiffusing material to cover the light emitting element, light emittedfrom the light emitting element can be widely radiated due to thediffusion effect of light diffusing material.

By composing such that, in the LED, the light diffusing material may bea phosphor, the phosphor is excited by light emitted from the lightemitting element and thereby excited light can be widely radiated.

Further, a light emitting diode (LED) of the invention comprises:

a light emitting element that is mounted on a power source supply meansand sealed with a sealing member of a transparent material; and

the sealing member that comprises a reflection surface and a sidereflection surface formed thereon, the reflection surface reflectinglight radiated from an emission surface of the light emitting elementand the side radiation surface radiating reflected light from thereflection surface and direct light form the light emitting element;

wherein the reflection surface has a solid angle of 2π{1−cos θc} orgreater to the light emitting element, where θc is a critical angle ofthe transparent material, and the side radiation surface is formed suchthat an incident angle of reflected light from the reflection surfaceand an incident angle of direct light from the light emitting elementare smaller than θc so as to externally radiate light emitted from thelight emitting element.

In this composition, light reflected by the reflection surface and thenproceeding nearly in parallel is passed directly through the sideradiation surface and externally radiated 360 degrees around the centeraxis of light emitting element nearly in a planar direction. Lightdirectly heading to the side radiation surface is externally radiateddirectly without being refracted by the side radiation surface. Thus,since no light to be radiated in the range of a small angle to thecenter axis exists, the radiation efficiency of light to be externallyradiated while being controlled as primary light from the side radiationsurface can be significantly enhanced.

Further, a light emitting diode (LED) of the invention comprises:

the lead frame that is protruded out of the transparent resin whilebeing bent under its mount surface from the vicinity of a mount positionof the light emitting element so as to reduce part of the lead framesealed with the transparent resin as much as possible.

By thus bending downward the lead frame while drawing it out of thetransparent resin, the embedded part is significantly reduced ascompared to that in being protruded in the horizontal direction of resinsince the lower part of a horizontal plane formed extending the mountsurface of light emitting element in transparent resin is considerablythinner than the upper part of the horizontal plane. Thereby, since heatof light emitting element is externally radiated in a short distance,heat is not accumulated in the light emitting element and lead frame.Also, since the contact area between the lead frame and the resindecreases, a crack at the boundary of the lead frame and the resin canbe prevented.

Further, the LED may comprise the lead frame that comprises part sealedwith the transparent resin that has a wide area sufficient to widelyconduct and disperse heat generated from the light emitting element.

Thus, heat to be conducted from the light emitting element directly tothe transparent resin and heat to be conducted from the light emittingelement through the lead frame to the transparent resin can be diffusedover the entire lead frame with the wide area. Thereby, a crack at theboundary of the light emitting element and the lead frame and thetransparent resin can be prevented that may be caused by the thermalexpansion by a remaining stress of transparent resin caused by heat tobe accumulated in the transparent resin.

Further, a light emitting diode (LED) of the invention comprises:

an light emitting section that comprises a two-dimensional directionreflection surface to reflect light emitted from a light emittingelement embedded in a transparent material at least in a two-dimensionaldirection; and

a reflector section that is optically connected at least around in thetwo-dimensional direction of the light emitting section and comprises areflection surface formed extending from the two-dimensional directionreflection surface.

Thus, the LED has the light emitting section with a two-dimensionaldirection reflection surface and the reflector section being opticallyconnected at least around there, and the reflector section has areflection surface formed extending from the two-dimensional directionreflection surface. Therefore, the LED is about the same as thetwo-dimensional direction reflection LED with a size of the reflector.Since a large solid angle can be formed to the light emitting element,the LED can have high radiation efficiency. Further, since the lightemitting section is in multiple arrays formed on the lead frame but canbe downsized, its interval is no more than the package diameter ascompared to the case of forming the same sold angle by light emittingelement sealing resin and therefore the number of yield can beincreased. Since the curing time of LED sealing resin is generally onehour or more, the LED can have a good mass productivity. Further, sincethe inner stress of LED sealing resin can be reduced as compared to thecase of forming the same sold angle by light emitting element sealingresin, no stress damage to the light emitting element and no crack inthe package occurs. Thus, the reliability can be enhanced. So, thetwo-dimensional direction radiation type LED can be obtained that has ahigh radiation efficiency, a good mass productivity and a highreliability.

The reflector section may be formed low-profile and additionally reflectlight reaching a surface opposite to the reflection surface of lightradiated from the light emitting section. Thereby, in addition to lightreflected by the reflection surface and radiated in the two-dimensionaldirection, light radiated from the light emitting section can beradiated in the two-dimensional direction based on total reflection atthe surface opposite to the reflection surface as well. The LED can havea further enhanced high radiation efficiency. Thus, the two-dimensionaldirection radiation type LED can be obtained that has a higher radiationefficiency, a good mass productivity and a high reliability.

The reflector may comprise a stepwise reflection surface that isopposite to the reflection surface and, in a direction perpendicular tothe two-dimensional direction, reflects light being reflected by thetwo-dimensional direction reflection surface and the reflection surfacein the two-dimensional direction. Thereby, without the reflection memberaround the LED, the reflector section serves as a reflection member toreflect light in the direction perpendicular to the two-dimensionaldirection. Therefore, the LED can be used for a downsized lamp with ahigh radiation efficiency. Further, the LED can have a good massproductivity and a high reliability.

The two-dimensional direction reflection surface of the light emittingsection may have a shape to be formed by rotating, around aperpendicular axis passing through the center of an emission surface ofthe light emitting element, part of ellipse, parabola, hyperbola or itsapproximated curve with a focal point at the light emitting element orits vicinity. Thereby, light reflected by the optical surface is alldirected in parallel with the horizontal plane and radiated in thetwo-dimensional direction. Further, since the upper surface of reflectorsection has a shape to follow that of the optical surface, lightreflected by the reflector's upper surface is all directed in parallelwith the horizontal plane and radiated in the two-dimensional direction.Thus, the LED can have a high radiation efficiency in thetwo-dimensional direction, a good mass productivity and a highreliability.

Further, a light emitting diode of the invention may comprise:

a light source section that comprises a circular cone portion that isopposite to an emission surface of a light emitting element embedded andis formed protruding outside; and

a reflection section that comprises a two-dimensional directionreflection surface that is connected at least to the circular coneportion and reflects light radiated from the light source section atleast in a two-dimensional plane direction.

Thereby, light radiated from the light source section and reflected bythe reflection section is radiated at least in the two-dimensional planedirection, and the entire LED serves as a two-dimensional directionradiation light source. Thus, even without the combination of lightemitting section and reflector section with a two-dimensional directionreflection surface to reflect light at least in the two-dimensionalplane direction, the LED can radiate light in the two-dimensionaldirection at a high radiation efficiency. Thus, the LED can have a highradiation efficiency in the two-dimensional direction, a good massproductivity and a high reliability.

Further, an LED light of the invention comprises:

an LED; and

a reflection mirror disposed around the LED;

wherein the LED comprises: a light emitting element mounted on a powersource supply means; a sealing means of a transparent material to sealthe light emitting element; a reflection surface that is opposite to anemission surface of the light emitting element and reflects lightemitted from the light emitting element in a direction orthogonal to thecenter axis of the light emitting element or in a direction at a largeangle to the center axis; and a side radiation surface that sidewardradiates light reflected by the reflection surface in a directionorthogonal to the center axis of the light emitting element or in adirection at a large angle to the center axis.

Thus, since light emitted from the light emitting element is evenlyreflected by the reflection surface of LED and then evenly radiated inthe direction nearly orthogonal to the center axis of the light emittingelement, the brightness of radiated light becomes uniform withoutdepending on position. By further reflecting light evenly emitted fromthe LED by the reflection mirror disposed around the LED, externalradiation light with a large area can be obtained.

By providing a central radiation surface that is disposed at the centerof the reflection surface and radiates light emitted from the lightemitting element in a direction nearly parallel to the center axis ofthe light emitting element, light upward radiated from the lightemitting element can be directly taken out. Therefore, the appearancecan be enhanced since the center of light emission is not blacked outand uniform light is given.

Further, an LED light of the invention may comprise:

an LED that comprises: a light emitting element mounted on a powersource supply means; and a sealing means of a transparent material toseal the light emitting element; wherein the sealing means comprises: areflection surface that reflects light emitted from the light emittingelement in a direction orthogonal to the center axis of the lightemitting element or in a direction at a large angle to the center axis;and a side radiation surface that sideward radiates light reflected bythe reflection surface; and the reflection surface has a shortestdistance from the light emitting element of less than ½ a radius R ofthe reflection surface so as to form a proximity optical system; and

a reflection mirror that reflects light radiated from the LED.

In this composition, since light emitted from the light emitting elementcan be radiated not only in the center axis direction but also in thedirection orthogonal to the center axis, and, since the radiation to thedirection orthogonal to the center axis increases according as thereflection surface comes close to the light emitting element, the LEDlight can have a light distribution characteristic with a wide radiationrange as well as a good visibility and a novel appearance.

Further, an LED light of the invention may comprise:

an LED that comprises: a light emitting element mounted on a powersource supply means; and a sealing means of a transparent material toseal the light emitting element; wherein the sealing means comprises: areflection surface that reflects light emitted from the light emittingelement in a direction orthogonal to the center axis of the lightemitting element or in a direction at a large angle to the center axis;and a side radiation surface that sideward radiates light reflected bythe reflection surface; and the reflection surface is formed such thatits radius R is greater than a height H from the emission surface of thelight emitting element to an edge of the reflection surface in thecenter axis direction of the light emitting element so as to form aproximity optical system; and

a reflection mirror that reflects light radiated from the LED.

In this composition, since light emitted from the light emitting elementcan be radiated not only in the center axis direction but also in thedirection orthogonal to the center axis, the LED light can have a lightdistribution characteristic with a wide radiation range.

The light emitting element may have a radiation intensity I(θ)represented by: I(θ)=k·cos θ+(1−k)·sin θ at an emission angle θ ofemitted light to the center axis direction, where k is a constant to bedetermined by a radiation intensity according to the emission angle θ ofthe light emitting element, and k≦0.8 is satisfied.

Thereby, since light emitted from the light emitting element can beradiated not only in the center axis direction but also in the directionorthogonal to the center axis, the LED light can have a lightdistribution characteristic with a wide radiation range.

Further, an LED light of the invention may comprise:

An LED light of the invention may comprise:

an LED that comprises: a light emitting element that is mounted on apower source supply means and sealed with a sealing member of atransparent material; and the sealing member that comprises a reflectionsurface and a side reflection surface formed thereon, the reflectionsurface reflecting light radiated from an emission surface of the lightemitting element and the side radiation surface radiating reflectedlight from the reflection surface and direct light form the lightemitting element; wherein the reflection surface has a solid angle of2π{1−cos θc} or greater to the light emitting element, where θc is acritical angle of the transparent material, and the side radiationsurface is formed such that an incident angle of reflected light fromthe reflection surface and an incident angle of direct light from thelight emitting element are smaller than θc so as to externally radiatelight emitted from the light emitting element; and

a reflection mirror that reflects light radiated from the LED.

In this composition, since light with a high radiation efficiency oflight to be externally radiated from the side radiation surface whilebeing controlled as primary light is reflected by the reflection mirror,the radiation efficiency can be significantly enhanced due to thereflection.

Further, an LED light of the invention may comprise:

a light emitting element;

a first reflection mirror that is formed on the light emitting elementand reflects light emitted from the light emitting element in the sidedirection; and

a second reflection mirror that upward reflects light from the firstreflection mirror.

In this composition, only by providing the first reflection mirror toreflect light emitted from the light emitting element in the sidedirection directly over the light emitting element, external radiationlight with a large area can be obtained as the second reflection mirrorto upward reflect this light is separated from the first reflectionmirror. Also, since light reflected in the side direction is alloptically controlled to be upward reflected and externally radiated, ahigh radiation efficiency can be obtained. Thus, the LED light can havea high radiation efficiency as well as a large radiation area by singlelight emitting element while utilizing the feature of LED, low-profile.

By providing a third reflection mirror that is disposed around the lightemitting element and upward reflects light sideward emitted from thelight emitting element, light can be also upward radiated from theperiphery of light emitting element whereas, in the LED light withoutthe third reflection mirror, light is upward radiated only directly overthe light emitting element. Therefore, the appearance can be enhancedsince the entire LED light further appears to radiate light.

By composing such that the first reflection mirror and the secondreflection mirror is formed into one optical member, the structure canbe simplified and a displacement between the first and second reflectionmirrors can be prevented. The LED light can securely have a highradiation efficiency.

By composing such that the second reflection mirror is in the shape of apolygon or its similar form when viewed from upward, a region with acertain shape can be lighted based on a combination of multiple samepolygons without reducing the external radiation efficiency. Therefore,it can be applied to a vehicle light etc.

By composing such that the light emitting element is mounted on acircuit board on a metal plate, the radiation property can besignificantly enhanced since the light emitting element is mounted onthe metal plate with a good thermal conductivity. Even when largecurrent is flown through the light emitting element, heat saturationdoes not occur. Therefore, a large optical output can be obtained. Thus,the LED light can be low-profile, with high brightness and can radiatelight in a large area as well as having an enhanced heat radiationproperty and offering a large optical output without being affected byheat saturation.

Further, a light emitting unit of the invention may comprise:

a light source that comprises: a light emitting element mounted on apower source supply means; a sealing means of a transparent material toseal the light emitting element; a first reflection surface that isopposite to an emission surface of the light emitting element andreflects light emitted from the light emitting element in a directionorthogonal to the center axis of the light emitting element or in adirection at a large angle to the center axis; and a side radiationsurface that sideward radiates light reflected by the first reflectionsurface in a direction orthogonal to the center axis of the lightemitting element or in a direction at a large angle to the center axis;and

a reflector that comprises a plurality of second reflection surfaces toreflect the light radiated from the side radiation surface in apredetermined radiation direction.

In this composition, since the position precision is secured byintegrally forming the light emitting element and the upper reflectionsurface, the positioning precision between the light source and thereflector only has to be controlled. Therefore, the trouble inassembling can be reduced and thereby the productivity can be enhanced,and a light radiation characteristic required can be easily obtained.

By composing such that, in the light emitting unit, the light sourcefurther comprises a central radiation surface that is disposed at thecenter of the first reflection surface and radiates light emitted fromthe light emitting element in a direction nearly parallel to the centeraxis of the light emitting element, light upward radiated from the lightemitting element can be directly taken out. Therefore, the appearancecan be enhanced since the center of light emission is not blacked out.

By composing such that, in the light emitting unit, the first reflectionsurface is formed close to the light emitting unit so as to increase alight receiving angle (solid angle) of the upper reflection surface, theoptical property can be enhanced based on the increased solid angle ofupper reflection surface and the bonding space in wire bonding and thespace for resin mold can be secured.

By composing such that, in the light emitting unit, the light source isdisplaced from the center and the position of optical control surfacesneighboring in the circumference direction is different from each otherin the radius direction, light can be also irradiated to the obliquereflection surface at the side surface of optical control surface.Therefore, when viewing the light emitting unit from outside thedirection to be subjected to the reflection by the optical controlsurface, reflected light can be confirmed at the oblique reflectionsurface to be formed by that the position of optical control surfacesneighboring in the circumference direction is different from each otherin the radius direction. Thus, the light emitting unit can have a largevisual recognition angle.

By composing such that, in the light emitting unit, the reflectorreflects the light, as the predetermined radiation direction, in adirection with a predetermined inclination to the center axis of thelight emitting element by the plurality of second reflection surfaces,uniform light can be radiated in a direction with a predeterminedinclination to the center axis of the light emitting element. The degreeof freedom in positioning the light emitting unit can be enhanced, andthe appearance can be enhanced.

By composing such that, in the light emitting unit, the reflector ismounted on an inclined section, the light emitting unit can below-profile and disposed along the inclination while offering a highexternal radiation efficiency.

By composing such that, in the light emitting unit, the plurality ofsecond reflection surfaces each has an optical control surface that itsangle and direction are set to allow reflected light to be reflected ina same direction, light can be reflected concentrated in a predeterminedoblique direction and the amount of light in this direction can beincreased. Thus, the light emitting unit can be low-profile and disposedalong the inclination while offering a high external radiationefficiency.

Further, a lamp of the invention comprises:

a plurality of light emitting units each of which comprises: a lightsource that comprises an optical system to radiate light emitted from alight emitting element in a direction orthogonal to the center axis ofthe light emitting element or in a direction at a large angle to thecenter axis; and a reflector that comprises a plurality of secondreflection surfaces to, in a predetermined direction, reflect the lightradiated from the light source in the direction orthogonal to the centeraxis of the light emitting element or in the direction at the largeangle to the center axis;

wherein the plurality of light emitting units are disposed in apredetermined arrangement.

In this composition, since light can be sufficiently irradiated to thereflector, the lamp can offer a high light utilization efficiency and anovel visual effect based on the arrangement of LED lights.

By composing such that, in the lamp, the light source has a lead framefixed on a board disposed on the back side of a housing, and its fixingposition corresponds to a penetration hole of the reflection mirror, theLED can be fixed at a certain position precision to the penetration holeby attaching the board at a certain position precision.

By composing such that, in the lamp, the board is, at the fixingposition, provided with a concave member into which the lead frame isinserted, the workability in assembling can be enhanced since theelectrical connection and positioning of LED can be conductedsimultaneously.

In the lamp, the light source may comprise: a light emitting elementmounted on a power source supply means; a sealing means of a transparentmaterial to seal the light emitting element; a first reflection surfacethat is opposite to an emission surface of the light emitting elementand reflects light emitted from the light emitting element in adirection orthogonal to the center axis of the light emitting element orin a direction at a large angle to the center axis; and a side radiationsurface that sideward radiates light reflected by the first reflectionsurface in a direction orthogonal to the center axis of the lightemitting element or in a direction at a large angle to the center axis.

Thereby, the deviation of light radiation property in multiple lightemitting units can be further reduced, and the visual effect inoperation can be enhanced.

In the lamp, the light source may comprise a plurality of LED's that arearranged radially such that an intersection point of the center axes ofthe plurality of LED's is a point on a same plane.

Thereby, the light utilization efficiency can be enhanced since lightemitted from the light emitting element is radiated along on the planewhile having directivity.

In the lamp, the plurality of light emitting units may be disposed suchthat part of the reflector of the neighboring light emitting units isoverlapped.

Thereby, a novel visual effect can be offer based on the combination ofmultiple light emitting units.

In the lamp, the plurality of light emitting units may include aplurality of light emitting units that are arranged at multiple stagesor in multiple rows, and the light emitting units at each stage includea plurality of light emitting units arranged linearly.

Thereby, a novel visual effect can be offer based on the combination ofmultiple light emitting units, and a visual recognition property and alight radiation property as a lamp can be enhanced.

In the lamp, the plurality of light emitting units may be arrangedthrough a partition plate to separate the plurality of light emittingunits arranged linearly.

Thereby, light radiated from the light emitting unit in operation can beefficiently irradiated to the radiation region.

In the lamp, the plurality of light emitting units may have a lightreflection finish on at least part of the circumference of the lightemitting unit or the partition plate.

Thereby, even when not in operation, a visual effect by external lightcan be obtained. Therefore, the lamp can offer an enhanced appearance, ahigh light utilization efficiency and a novel visual effect.

In the lamp, the plurality of light emitting units may be disposed suchthat the neighboring light emitting units are arranged at differentstages in the center axis direction.

Thereby, a visual effect with a depth feel can be offered regardless ofin operation or not.

In the lamp, the plurality of light emitting units may be composed suchthat a plurality of reflection surfaces are concentric disposed aroundthe light source.

Thereby, light to be radiated in a direction nearly orthogonal to thecenter axis can be efficiently reflected and radiated in a directionalong the center axis.

In the lamp, the plurality of reflection surfaces may be formed nearlyplanar.

Thereby, the lamp can be low-profile without lowering the lightradiation property.

1. A light emitting diode (LED), comprising: a light emitting elementmounted on a power source supply means and having a wide lightdistribution characteristic; and a sealing means of a transparentmaterial to seal the light emitting element, wherein the sealing meanscomprises: an upper reflection surface having a reflection mirror thatreflects light emitted from the light emitting element in a directionorthogonal to a center axis of the light emitting element; a sideradiation surface that sideward radiates light reflected by the upperreflection surface; and a central radiation surface placed at a centerof the upper reflection surface, in which an increment of solid angle ofthe central radiation surface directly externally radiates light emittedfrom the light emitting element via the reflection mirror in a directionnearly parallel to the center axis, wherein the central radiationsurface has a shortest distance from the light emitting element of lessthan ½ a radius R of the upper reflection surface to form a proximityoptical system, and wherein an upper surface of the central radiationsurface is exposed to an outside of the light emitting diode.
 2. Thetight emitting diode according to claim 1, wherein: the light emittingelement has a radiation intensity I(θ) represented by: I(θ)=k cosθ+(1−k)sin θ at an emission angle θ of emitted light to the center axisdirection, where k is a constant to be determined by a radiationintensity according to the emission angle θ of the light emittingelement, and k≦0.8 is satisfied.
 3. The light emitting diode accordingto claim 1, wherein: the light emitting element comprises a transparentsubstrate to have a light transmitting property to light emittedtherefrom.
 4. The light emitting diode according to claim 1, wherein:the sealing means comprises a light diffusing material to cover thelight emitting element.
 5. The light emitting diode according to claim4, wherein: the light diffusing material comprises a phosphor.
 6. Thelight emitting diode according to claim 1, wherein: the reflectionsurface has a solid angle of 2π{1−cos θc} or greater to the lightemitting element, where θc is a critical angle of the transparentmaterial, and the side radiation surface is formed such that an incidentangle of reflected light from the reflection surface and an incidentangle of direct light from the light emitting element are smaller thanθc so as to externally radiate light emitted from the light emittingelement.
 7. The light emitting diode according to claim 1, furthercomprising: a lead frame to supply electric power to the light emittingelement mounted thereon, wherein the sealing means seals the lightemitting element and the lead frame, and the lead frame comprises aconductive material with a high thermal conductivity of 300 W/mk or moreand is protruded out of the transparent resin while being bent under itsmount surface from a vicinity of a mount position of the light emittingelement so as to reduce a part of the lead frame sealed with thetransparent resin as much as possible.
 8. The light emitting diodeaccording to claim 1, further comprising: a lead frame to supplyelectric power to the light emitting element mounted thereon, whereinthe sealing means seals the light emitting element and the lead frame,and the lead frame comprises a part sealed with the transparent resinthat has a wide area sufficient to widely conduct and disperse heatgenerated from the light emitting element and comprises a conductivematerial with a high thermal conductivity of 300 W/mk or more.
 9. Thelight emitting diode according to claim 1, further comprising: a leadframe to supply electric power to the light emitting element mountedthereon, wherein the sealing means seals the light emitting element andthe lead frame and comprises: a first transparent resin to seal thelight emitting element and a part of the lead frame; and a secondtransparent resin disposed in contact with and around a side of thefirst transparent resin.
 10. A light emitting unit, comprising: the LEDdefined in claim 1; and a reflector that comprises a plurality of secondreflection surfaces to reflect a light radiated from the side radiationsurface in a predetermined radiation direction.
 11. A lamp, comprising:a plurality of light emitting units each of which comprises: the LEDdefined in claim 1; and a reflector that comprises a plurality of secondreflection surfaces to, in a predetermined direction, reflect a lightradiated from a light source in the direction orthogonal to the centeraxis of the light emitting element or in a direction at a large angle tothe center axis, wherein the plurality of light emitting units aredisposed in a predetermined arrangement.
 12. The lamp according to claim11, wherein: the LED has a lead frame fixed on a board disposed on aback side of a housing, and its fixing position corresponds to apenetration hole of the reflection mirror.
 13. The lamp according toclaim 11, wherein: the LED comprises: a light emitting element mountedon a power source supply means; a sealing means of a transparentmaterial to seal the light emitting element; a first reflection surfacethat opposite to an emission surface of the light emitting element andreflects light emitted from the light emitting element in a directionorthogonal to the center axis of the light emitting element or in adirection at a large angle to the center axis, and a side radiationsurface that sideward radiates light reflected by the first reflectionsurface in a direction orthogonal to the center axis of the lightemitting element or in a direction at a large angle to the center axis.14. The lamp according to claim 11, wherein: the LED comprises aplurality of LED's that are arranged radially such that an intersectionpoint of the center axes of the plurality of LED's is a point on a sameplane.
 15. The lamp according to claim 11, wherein: the plurality oflight emitting units are disposed such that a part of the reflector ofthe neighboring light emitting units is overlapped.
 16. The lampaccording to claim 11, wherein: the plurality of light emitting unitsinclude a plurality of light emitting units that are arranged atmultiple stages or in multiple rows, and the light emitting units ateach stage include a plurality of light emitting units arrangedlinearly.
 17. The lamp according to claim 16, wherein: the plurality oflight emitting units are arranged through a partition plate to separatethe plurality of light emitting units arranged linearly.
 18. The lampaccording to claim 11, wherein: the plurality of light emitting unitshave a light reflection finish on at least a part of the circumferenceof the light emitting unit or the partition plate.
 19. The lampaccording to claim 11, wherein: the plurality of light emitting unitsare disposed such that neighboring light emitting units are arranged atdifferent stages in the center axis direction.
 20. The lamp according toclaim 11, wherein: the plurality of light emitting units are composedsuch that a plurality of reflection surfaces are concentrically disposedaround the LED.
 21. The lamp according to claim 20, wherein: theplurality of reflection surfaces are formed to be nearly planar.
 22. Thelight emitting diode according to claim 1, wherein the sealing meansextends up to an edge of the upper reflection surface located on anintersection of the side radiation surface with the upper reflectionsurface.
 23. The light emitting diode according to claim 1, wherein thereflection mirror reflects light emitted from the light emitting elementin the direction orthogonal to the center axis of the light emittingelement within the sealing means.
 24. The light emitting diode accordingto claim 1, wherein the central radiation surface radiates, directly toan outside of the light emitting diode, a light emitted from the lightemitting element in the direction nearly parallel to the center axis.25. A light emitting diode (LED), comprising: a light emitting elementmounted on a power source supply means and having a wide lightdistribution characteristic; and a sealing means of a transparentmaterial to seal the light emitting element, wherein the sealing meanscomprises: an upper reflection surface having a reflection mirror thatreflects light emitted from the light emitting element in a direction,orthogonal to a center axis of the light emitting element; a sideradiation surface that sideward radiates light reflected by the upperreflection surface; and a central radiation surface placed at a centerof the upper reflection surface, in which an increment of solid angle ofthe central radiation surface directly externally radiates light emittedfrom the light emitting element in a direction nearly parallel to thecenter axis, wherein the upper reflection surface is formed such thatits radius R is greater than a height H from an emission surface of thelight emitting element to an edge of the upper reflection surface in thecenter axis direction of the light emitting element so as to form aproximity optical system, and wherein an upper surface of the centralradiation surface is exposed to an outside of the light emitting diode.26. The light emitting diode according to claim 25, wherein: the lightemitting element has a radiation intensity I(θ) represented by: I(θ)=kcos θ+(1−k)sin θ at an emission angle θ of emitted light to the centeraxis direction, where k is a constant to be determined by a radiationintensity according to the emission angle θ of the light emittingelement, and k≦0.8 is satisfied.
 27. The light emitting diode accordingto claim 25, wherein: the light emitting element comprises a transparentsubstrate to have a light transmitting property to light emittedtherefrom.
 28. The light emitting diode according to claim 25, wherein:the sealing means comprises a light diffusing material to cover thelight emitting element.
 29. The light emitting diode according to claim25, wherein: the reflection surface has a solid angle of 2π{1−cos θc} orgreater to the light emitting element, where θc is a critical angle ofthe transparent material, and the side radiation surface is formed suchthat an incident angle of reflected light from the reflection surfaceand an incident angle of direct light from the light emitting elementare smaller than θc so as to externally radiate light emitted from thelight emitting element.
 30. The light emitting diode according to claim25, further comprising: a lead frame to supply electric power to thelight emitting element mounted thereon, wherein the sealing means sealsthe light emitting element and the lead frame, and the lead framecomprises a conductive material with a high thermal conductivity of 300W/mk or more and is protruded out of the transparent resin while beingbent under its mount surface from a vicinity of a mount position of thelight emitting element so as to reduce a part of the lead frame sealedwith the transparent resin as much as possible.
 31. The light emittingdiode according to claim 25, further comprising: a lead frame to supplyelectric power to the light emitting element mounted thereon, whereinthe sealing means seals the light emitting element and the lead frame,and the lead frame comprises a part sealed with the transparent resinthat has a wide area sufficient to widely conduct and disperse heatgenerated from the light emitting element and comprises a conductivematerial with a high thermal conductivity of 300 W/mk or more.
 32. Thelight emitting diode according to claim 25, further comprising: a leadframe to supply electric power to the light emitting element mountedthereon, wherein the sealing means seals the light emitting element andthe lead frame and comprises: a first transparent resin to seal thelight emitting element and a part of the lead frame; and a secondtransparent resin disposed in contact with and around a side of thefirst transparent resin.
 33. A light emitting unit, comprising: the LEDdefined in claim 25; and a reflector that comprises a plurality ofsecond reflection surfaces to reflect a light radiated from the sideradiation surface in a predetermined radiation direction.
 34. A lamp,comprising: a plurality of light emitting units each of which comprises:the LED defined in claim 25, and a reflector that comprises a pluralityof second reflection surfaces to, in a predetermined direction, reflecta light radiated from a light source in the direction orthogonal to thecenter axis of the light emitting element or in a direction at a largeangle to the center axis, wherein the plurality of light emitting unitsare disposed in a predetermined arrangement.
 35. The light emittingdiode according to claim 25, wherein the sealing means extends up to theedge of the upper reflection surface such that the side radiationsurface intersects with the upper reflection surface at the edge of theupper reflection surface.
 36. The light emitting diode according toclaim 25, wherein the reflection mirror reflects light emitted from thelight emitting element in the direction orthogonal to the center axis ofthe light emitting element within the sealing means.
 37. The lightemitting diode according to claim 25, wherein the central radiationsurface radiates, directly to an outside of the light emitting diode,the light emitted from the light emitting element in the directionnearly parallel to the center axis.
 38. A light emitting diode,comprising: a light emitting element mounted on a power source supplymeans and having a wide light distribution characteristic; and a sealingmeans of a transparent material to seal the light emitting element, thesealing means comprising: an upper reflection surface having areflection mirror that reflects light emitted from the light emittingelement in a direction orthogonal to a center axis of the light emittingelement within the sealing means; a side radiation surface that sidewardradiates light reflected by the upper reflection surface; and a centralradiation surface placed at a center of the upper reflection surface, inwhich an increment of solid angle of a central radiation surfacedirectly externally radiates light emitted from the light emittingelement via the reflection mirror in a direction nearly parallel to thecenter axis, wherein the sealing means extends up to an edge of theupper reflection surface located on an intersection of the sideradiation surface with the upper reflection surface, and wherein anupper surface of the central radiation surface is exposed to an outsideof the light emitting diode.
 39. The light emitting diode according toclaim 38, wherein the central radiation surface has a shortest distancefrom the light emitting element of less than ½ a radius R of the upperreflection surface to form a proximity optical system.
 40. The lightemitting diode according to claim 38, wherein the central radiationsurface radiates, directly to an outside of the light emitting diode,the light emitted from the light emitting element in the directionnearly parallel to the center axis.